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101.
We confirm the presence of pigmented keratinized integumentary structures attributable to feathers in the Late Cretaceous Ornithomimus specimen UALVP 52531. We falsify the hypothesis that these features represent collagen fibers and address additional criticisms of our paper made by Lingham-Soliar (2016).  相似文献   
102.
运用傅立叶变换红外光谱(FTIR)技术,对大别山碧溪岭和黄镇榴辉岩中的绿辉石进行了详细的结构水观察。绿辉石中普遍含有结构水,以OH~-的形式存在,含量可达~2000ppm(H_2O wt.)。碧溪岭绿辉石的水含量在露头尺度(-150km)上是不均一的,而黄镇绿辉石是均一的(至少在3km的尺度上)。碧溪岭绿辉石水含量的不均一分布和黄镇绿辉石水含量的均一分布都反映的是原岩特征,碧溪岭榴辉岩原岩经历的水-岩相互作用是“隧道式”的而黄镇是“弥散式”的碧溪岭榴辉岩的原岩可能是基性的侵入岩而黄镇榴辉岩的原岩可能是玄武岩。碧溪岭绿辉石的水含量(<1400ppm)明显低于黄镇绿辉石(~1850ppm),这是原岩水含量差异的体现,原岩性质的不同和经历的水-岩相互作用方式的不同造成了原岩水含量的差异。  相似文献   
103.
应用FTIR光谱技术系统测定了海洋固体颗粒主要无机组份(包括粘土、金属氧化物和碳酸钙)在2500~4000cm~(-1)范围内的红外光谱。着重研究了这些海洋固体颗粒的表面自由羟基、表面氢键羟基和结构羟基的伸缩振动红外吸收峰及其特征。  相似文献   
104.
Potential protonation sites for, kyanite, sillimanite, and andalusite, located in a mapping of the (3, −3) critical points displayed by their L(r) = −∇2ρ(r) distributions, are compared with polarized single-crystal FTIR spectra of kyanite and sillimanite determined earlier and with andalusite measured in this study. For andalusite, seven peaks were observed when the electric vector, E, is parallel to [100]: four intense ones at 3,440, 3,460, 3,526, and 3,597 cm−1 and three weaker ones at 3,480, 3,520, and 3,653 cm−1. Six peaks, three intense ones at 3,440, 3,460, and 3,526 cm−1 and three weaker ones at 3,480, 3,520, and 3,653 cm−1 when E parallels [010]. No peaks were observed when E is parallel to [001]. The concentration of water in andalusite varies between 110 and 168 ppm by weight % H2O. Polarized FTIR spectra indicate that the OH vector is parallel to (001) in andalusite and sillimanite and in kyanite. Examination of the L(r) (3, −3) critical points in comparison with the polarized FTIR indicates that H prefers to bond to the oxygen atoms O1 and O2 in andalusite and O2 and O4 in sillimanite which correspond to the underbonded oxygen atoms and those with the largest L(r) maxima. In kyanite, comparison of the FTIR spectrum and the critical points indicates that H will preferentially bond to the two 4-coordinated O2 and O6 atoms.  相似文献   
105.
To assess settling particulate organic matter (POM) seasonality and its availability to the benthic community, settling particulate matter was studied in terms of mass fluxes and main biogeochemical characteristics (including organic carbon (OC), nitrogen, and stable carbon and nitrogen isotopic values) at two Lake Superior offshore sites over the course of a year. Fourier transform infrared spectroscopy (FTIR) and hydrolysis, extraction, and derivatization were used to provide further compositional information. Carbon and nitrogen content, isotopic and wet chemical data, and FTIR spectra show that summer particulate material is mainly autochthonous, with higher proportions of amide and carbohydrate. FTIR shows that spring particulate material contains relatively high proportions of clay minerals, indicating major sources from sediment resuspension and/or spring runoff. Distinct amino acid distributions at the two sites, revealed by principal component analysis (PCA) based on amino acid mol% composition, possibly result from differences in OM sources and the degree of degradation occurring at the two sites. Carbohydrate (PCHO), total hydrolyzable amino acid (THAA) and FTIR data suggest that the nutritional value of bulk POM to benthic heterotrophs should be lower in spring than summer-fall, although both periods exhibited high sinking fluxes of total mass and OC. Due to sediment resuspension events and an oxic water column, organic matter eventually buried in Lake Superior’s sediments has probably experienced extensive alteration due to several cycles through the water column and the bacterially-active sediment-water interface.  相似文献   
106.
主要探讨短小芽孢杆菌与钙基蒙脱石相互作用过程中的现象及机理。SEM结果显示,大量土壤菌黏附、包裹于蒙脱石表面。加入蒙脱石后,短小芽孢杆菌-钙基蒙脱体系中有机酸含量明显降低。XRD结果表明,短小芽孢杆菌作用后蒙脱石层间距增大,001面衍射峰钝化。FTIR显示作用后蒙脱石出现了来自于土壤菌的新峰,其他基团峰出现蓝移或红移现象。经二阶导数红外光谱分析验证,蒙脱石中确实出现了来自于土壤菌的其他基团振动,揭示土壤菌代谢产物进入蒙脱石层间域内的初步可能性,这将为矿物-微生物相互作用间的机理研究提供新依据。  相似文献   
107.
对山东郯城砂矿中的金刚石开展了傅里叶红外光谱和显微激光拉曼光谱的测试,结果显示,红外光谱均可见C—C的本征峰;绝大多数可见氮的吸收峰:双氮的吸收峰、聚合氮的吸收峰和氮片晶的吸收峰;部分可见氢的吸收峰:C—H的吸收峰、C—N的吸收峰和H2O的吸收峰.郯城金刚石以Ⅰa型金刚石为主,有ⅠaA、ⅠaB、ⅠaAB型,而Ⅱa型仅1粒;氮类型包括双氮(A心)、聚合氮(B心)及氮片晶(B'心),说明金刚石中的孤氮(C心)已经转化为双原子氮,但部分双原子氮未完成进一步的聚形.金刚石拉曼峰值集中在1131 cm–1,拉曼位移漂移程度较小,说明金刚石内部应力发生小幅的变化.在郯城金刚石中首次发现柯石英包裹体,出现139 cm–1、152 cm–1、212 cm–1、272 cm–1、328 cm–1、356 cm–1、428 cm–1和529 cm–1左右的拉曼峰值.在1粒金刚石中柯石英包裹体数量多达十余个,直径几μm至几十μm,呈针状、哑铃状、浑圆状和短柱状等多种形态.郯城金刚石中柯石英包裹体的出现,可作为郯城地区存在榴辉岩型金刚石的可靠标志,也佐证了该地部分金刚石的来源可能和洋壳循环或者俯冲过程有关.镁橄榄石包裹体上覆分散的黑色石墨斑点,与山东蒙阴、辽宁和湖南金刚石中的镁橄榄石等不同种类包裹体具有相似特征,推测这些石墨斑点是晶体包裹体形成后,由于外部环境温压条件的变化产生.  相似文献   
108.
本文主要以湖北天然绿松石、浸胶绿松石和注有色胶绿松石为研究对象,结合优化处理工艺过程及所用的胶水混合液,通过宝石学常规测试以及扫描电子显微镜、红外光谱仪、激光拉曼光谱仪和紫外可见光谱仪等宝石学现代仪器的测试分析,研究有效鉴别湖北天然绿松石和浸胶绿松石、注有色胶绿松石的测试方法。结果表明,注有色胶绿松石的颜色较呆板,浸胶和注有色胶绿松石相对密度较低且在长波紫外荧光灯下显示强至弱的蓝色荧光;扫描电镜下可见浸胶和注有色胶绿松石微晶之间的空隙被不同程度的胶质物充填,但该方法为有损法,不推荐使用;红外光谱中2 930、2 860、1 730、1 460 cm-1附近由有机物基团振动所致的红外吸收谱带可有效区分三者,是最为快速、无损、准确的方法;拉曼光谱中2 942、2 873、1 452、1 620、830 cm-1附近的吸收峰可作为鉴别湖北天然绿松石和浸胶或注有色胶绿松石的重要依据;紫外可见光谱中较弱的429 nm吸收峰和宽缓的677 nm吸收带可作为区分天然绿松石和注有色胶绿松石的鉴别依据,但无法区分天然绿松石和浸胶绿松石。  相似文献   
109.
Plastics and beaches: a degrading relationship   总被引:6,自引:0,他引:6  
Plastic debris in Earth's oceans presents a serious environmental issue because breakdown by chemical weathering and mechanical erosion is minimal at sea. Following deposition on beaches, plastic materials are exposed to UV radiation and physical processes controlled by wind, current, wave and tide action. Plastic particles from Kauai's beaches were sampled to determine relationships between composition, surface textures, and plastics degradation. SEM images indicated that beach plastics feature both mechanically eroded and chemically weathered surface textures. Granular oxidation textures were concentrated along mechanically weakened fractures and along the margins of the more rounded plastic particles. Particles with oxidation textures also produced the most intense peaks in the lower wavenumber region of FTIR spectra. The textural results suggest that plastic debris is particularly conducive to both chemical and mechanical breakdown in beach environments, which cannot be said for plastics in other natural settings on Earth.  相似文献   
110.
Here we report measurements of the chemical composition and flux of gas emitted from the central lava lake at Erta 'Ale volcano (Ethiopia) made on 15 October 2005. We determined an average SO2 flux of ∼ 0.69 ± 0.17 kg s− 1 using zenith sky ultraviolet spectroscopy of the plume, and molar proportions of magmatic H2O, CO2, SO2, CO, HCl and HF gases to be 93.58, 3.66, 2.47, 0.06, 0.19 and 0.04%, respectively, by open-path Fourier transform infrared (FTIR) spectrometry. Together, these data imply fluxes of 7.3, 0.7, 0.008, 0.03 and 0.004 kg s− 1 for H2O, CO2, CO, HCl and HF, respectively. These are the first FTIR spectroscopic observations at Erta 'Ale, and are also some of the very few gas measurements made at the volcano since the early 1970s (Gerlach, T.M., 1980b. Investigation of volcanic gas analyses and magma outgassing from Erta 'Ale lava lake, Afar, Ethiopia. Journal of Volcanology and Geothermal Research, 7(3–4): 415–441). We identify significant increases in the proportion of H2O in the plume with respect to both CO2 and SO2 across this 30-year interval, which we attribute to the depletion of volatiles in magma that sourced effusive eruptions during the early 1970s and/or to fractional magma degassing between the two active pit craters located in the summit caldera.  相似文献   
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