Tholeiitic basalts from spreading ocean ridges the growth of the oceanic crust

The oceanic earth's crust has mainly grown from magmatic productivity in spreading meridional ridges during the past 100–200 million years. The specific rock formed from these magmas is the ocean ridge tholeiitic basalt (ORT). From both melting experiments on peridotites and relative abundances of incompatible elements (La, Ce, Th, Rb etc.) the tholeiitic magmas can be explained as products of about 15% partial melting of abundant upper mantle rocks. A mobilization of incompatible elements very late in the mantle history has formed the different source rocks for magmas and ORT basalts depleted or slightly enriched in incompatible elements.     

基于水文地球化学信息和环境同位素的地下热水成因分析

以海南省乐东县福报地热田内分布的基岩热水井为研究对象,利用水文地球化学信息和环境同位素技术分析地下热水的形成机制。结果显示,本区地下热水以高偏硅酸、低矿化度为特征,水化类型为HCO_3-Ca型。氢氧同位素特征、Cl-SO_4-HCO_3及Na-K-Mg三线图表明,本区地下热水主要来源于大气降水,受地壳深部地热水影响较少。地下热水中~3H、~(14)C同位素年龄测定结果表明区域地下热水不存在大尺度的径流模型,且在出露过程中混入了常温水。     

Teleskope und Detektoren für die Infrarot-Astronomie

Infrared observations with ground-based and balloon-borne telescopes are hampered by thermal background radiation and absorption caused by the earth's atmosphere. A sensitivity gain of up to three orders of magnitude can be obtained under the low photon background conditions of a helium-cooled space telescope. Physical properties of photodetectors and bolometers as well as their application to the new infrared telescopes aboard satellites and Spacelab are discussed.     

Das Erdbild der Jurazeit

The term “Jurassic” refers to a manifold rock series of an epoch in the earth's history and its organic enclosures, from which-despite the lack of detail -a picture of earth surface and its life at that time can be reconstructed. This article presents the position of research and the problems it faces, which are partly of an objective and partly of a methodical nature.     

Photobiologische Umwandlung der Sonnenenergie

Photosynthesis converts sunlight into chemical energy. The photosynthetic buildup of biomass is the biggest global production process although its average efficiency is only about 0.13% with respect to the radiation energy reaching the earth's surface. This is primarily due to limiting physiological factors such as CO₂, water, and fertilizer. By turning off biomass production from the photosynthetic mechanism these restraints are excluded, and the photolytic system of the photosynthetic apparatus can be used for reduction of protons. This leads to free hydrogen gas with a comparatively high theoretical efficiency.     

Die Entwicklung der Erdrinde

The key and the well established basis for our present understanding of the evolution of the earth's lithosphere is the continous creation of new oceanic lithosphere in the mid oceanic ridge system. Paleomagnetic evidence and the concept of global plate tectonics permit a quantitative reconstruction of the kinematic history of the lithosphere for the past 200 m.y. This leads to continent configurations very similar to those proposed by A. Wegener. Plate tectonic processes can be traced back until Precambrian times. Before that, due to the generally higher temperature of the earth, the evolution was apparently governed by different processes. Thermal convection and gravitational instabilities are considered as driving forces for the lithosphere.     

南岔区仙翁山风景区生态旅游资源开发初探

南岔区仙翁山是集石、树、崖、壁、洞、岩、花、草、藤、果、药、水于一体的巨大自然博物馆,适合开发生态旅游项目。应遵循生态旅游理念确定开发原则、开发措施以及一些管理方法,达到旅游、观光和保护自然环境可持续发展的目的。     

Preparing future engineers for challenges of the 21st century: Sustainable engineering

The field of engineering is changing rapidly as the growing global population puts added demands on the earth's resources: engineering decisions must now account for limitations in materials and energy as well as the need to reduce discharges of wastes. This means educators must revise courses and curricula so engineering graduates are prepared for the new challenges as practicing engineers. The Center for Sustainable Engineering has been established to help faculty members accommodate such changes through workshops and new educational materials, including a free access website with peer-reviewed materials.     

The Oklo phenomenon

Until recently, scientists believed that the chemical elements were synthesized only in stars. The discovery of the Oklo phenomenon in the Republic of Gabon in 1972 has revealed, however, that a nuclear “fire” had existed on the earth and largescale transmutations of the elements were occurring on our planet 1.7·10⁹ years ago. The formation of natural (or Pre-Fermi) reactors is closely related to the appearance of life on our planet earth. The Pre-Fermi reactors were probably never formed until about 2·10⁹ years ago, when oxygen was injected into the earth's atmosphere by a new generation of living organisms carrying out photosynthesis.     

海岸线变迁及驱动因素进展研究

海岸线是陆地和海洋的分界线,是地球表层生态环境最敏感、响应全球变化最迅速的生态脆弱带,中国海岸线类型丰富,总长度达32 000多千米,因此,研究海岸线的变迁及其驱动因素具有重要的现实意义.文章首先总结了海岸线的定义及分类,探讨了海岸线定义不明确的问题;然后讨论了国内外利用遥感影像提取海岸线的方法及存在的问题,总结了海岸线的时空变迁及其驱动力研究进展状况,分析了国内外研究的差异;最后针对现有研究的不足,提出几点建议.     

Individual particle analysis of aerosols collected at Lhasa City in the Tibetan Plateau

To understand the composition and major sources of aerosol particles in Lhasa City on the Tibetan Plateau (TP), individual particles were collected from 2 February to 8 March, 2013 in Tibet University. The mean concentrations of both PM_2.5 and PM₁₀ during the sampling were 25.7 ± 21.7 and 57.2 ± 46.7 μg/m³, respectively, much lower than those of other cities in East and South Asia, but higher than those in the remote region in TP like Nam Co, indicating minor urban pollution. Combining the observations with the meteorological parameters and back trajectory analysis, it was concluded that local sources controlled the pollution during the sampling. Transmission electron microscopy (TEM) combined with energy-dispersive X-ray spectra (EDS) was used to study 408 particles sampled on four days. Based on the EDS analysis, a total of 8 different particle categories were classified for all 408 particles, including Si-rich, Ca-rich, soot, K-rich, Fe-rich, Pb-rich, Al-rich and other particles. The dominant elements were Si, Al and Ca, which were mainly attributed to mineral dust in the earth's crust such as feldspar and clay. Fe-, Pb-, K-, Al-rich particles and soot mainly originated from anthropogenic sources like firework combustion and biomass burning during the sampling. During the sampling, the pollution mainly came from mineral dust, while the celebration ceremony and religious ritual produced a large quantity of anthropogenic metal-bearing particles on 9 and 25 February 2013. Cement particles also had a minor influence. The data obtained in this study can be useful for developing pollution control strategies.     

黄土高原关键带土壤水分空间分异特征

地球关键带是人类生存和发展的关键区域。关键带发生的一系列物理、化学和生物过程与人类活动密切相关。土壤水分是黄土高原关键带的关键要素,同时又是黄土高原植被恢复与生态环境重建的决定因子。为揭示黄土高原关键带土壤水分的空间分异特征,采用网格(50m×50m)布点,雨季结束后采集0~500cm深度土壤样品,结合室内分析,结果表明:黄土高原小流域中73个样点0~500cm的土壤含水量分布范围介于1%~23%之间,降水对0~100cm土层的土壤水分补充明显;土壤水分在水平和垂直方向都表现出明显的空间异质性,在不同方向上的水分控制过程有所不同,是对土地利用方式、植被类型、地形要素、土壤质地等多因素综合响应的结果。充分理解关键带土壤水分空间的分异规律及其主控因素有助于该区小流域综合治理中的植被建造与布局,也有助于对该区土壤水文和生物地球化学过程的理解。     

Magnetic and other field effects on prochiral chemical reactions

Experiments are reported in which three prochiral organic reactions were conducted in the presence of a ca. 1T magnetic field which was oriented with reference to the earth's geometric axes. The sign and magnitude of the rotation varied with the macroscopic orientation of the magnetic field and the time that the reaction was performed. Control measurements were in accord with expectations. The fact that the sign of the observed optical rotation of the product was reversed for all three reported reactions when the magnetic field was reversed for reactions conducted on the same day suggests that either the observed asymmetric synthesis was due to the reactions being conducted in a chiral physical field or extremely unusual stochastic processes were involved.     

Equal Opportunity for Biomass in Greenhouse Gas Accounting of CO2 Capture and Storage: A Step Towards More Cost-Effective Climate Change Mitigation Regimes

Carbon dioxide capture and permanent storage (CCS) is one of the most frequently discussed technologies with the potential to mitigate climate change. The natural target for CCS has been the carbon dioxide (CO₂) emissions from fossil energy sources. However, CCS has also been suggested in combination with biomass during recent years. Given that the impact on the earth's radiative balance is the same whether CO₂ emissions of a fossil or a biomass origin are captured and stored away from the atmosphere, we argue that an equal reward should be given for the CCS, independent of the origin of the CO₂. The guidelines that provide assistance for the national greenhouse gas (GHG) accounting under the Kyoto Protocol have not considered CCS from biomass (biotic CCS) and it appears that it is not possible to receive emission credits for biotic CCS under the first commitment period of the Kyoto Protocol, i.e., 2008–2012. We argue that it would be unwise to exclude this GHG mitigation alternative from the competition with other GHG mitigation options. We also propose a feasible approach as to how emission credits for biotic CCS could be included within a future accounting framework.     

九寨沟世界自然遗产核心景区钙华景观的研究进展与展望

九寨沟钙华是距今约3万年(特别是1万年)以来逐渐形成的。大规模的钙华沉积是湖泊、滩流、瀑布、泉及台地景观形成的基础,覆盖核心景区2.4 km²的面积。钙华景观是九寨沟遗产地突出普遍价值——"自然美学价值"的核心,是景区的关键吸引力。为九寨沟的持续保护和为未来研究提供支持,本文从钙华沉积物、钙华景观成因、钙华景观变化及其原因、钙华景观保护恢复的角度,总结了公开和未公开发表的研究结果。针对目前钙华景观保护面临的主要问题(钙华退化、藻类生物量增加、沼泽化),本文归纳了相关的自然与人为因素,包括气候变暖、大气沉降、水化学变化、旅游活动、森林采伐、地质灾害等;归纳了地震和滑坡等地质灾害对钙华景观形成与重塑的双重作用;总结了钙华景观保护恢复的管理工作及其成效。本文提出未来可重点研究:(1)气候变化和人为活动背景下多圈层(大气、陆地生态系统、水生生态系统和基岩系统)对水体氮、磷、溶解性有机物、绿藻生物量、钙华沉积与溶蚀的影响机制及程度;(2)2017年九寨沟7.0级地震后,自然与人为干预下钙华微地貌的长期稳定性,水土流失加剧对湖泊透明度、钙华、沼泽化及美学价值的长期影响,地质灾害及其防治对钙华景观的长期效应。     

Reinforcement of thermoplastic rejects in the production of manhole covers

Thermoplastic rejects are un-recyclable plastics that are either incinerated causing harmful emissions into the air or land-filled. A common problem associated with manhole covers is the theft of the cover made out of cast iron and then selling it on the black market leaving a large empty hole in the road causing many potential safety and health hazards. This paper investigates the reinforcement of un-recyclable thermoplastic rejects to be used in the application of a manhole cover. Foundry sand and steel were used with the thermoplastic rejects as reinforcement of the material. Foundry sand is a hazardous waste that may cause many potential health hazards. It was shown that with 10% foundry sand, 90% thermoplastic rejects, and a steel mesh of diameter size 12 mm reinforcement, the manhole cover could withstand an average load of 112 kN. This value exceeds Grades A, AA, AAA, and B of acclaimed standards BS EN 124 for manhole covers, which ultimately indicates that the manhole cover may be used in pedestrian precincts and areas with occasional vehicular access. This composite material is produced out of waste materials (foundry sand and un-recyclable thermoplastic rejects) thus not utilizing or depleting the earth's natural resources, and eliminating the safety hazards, health hazards, and pollution associated with these waste materials. Not only is this product a benefit to the environment, but also inexpensive due to the fact that the materials are un-recyclable waste materials, and thus do not attain any value or cost.     

The isostatic state of the southern Urals crust

The Uralide orogen, in Central Russia, is the focus of intense geoscientific investigations during recent years. The international research is motivated by some unusual lithospheric features compared with other collisional belts including the preservation of (a) a collisional architecture with an orogenic root and a crustal thickness of 55–58 km, and (b) large volumes of very low-grade and non-metamorphic oceanic crust and island arc rocks in the upper crust of a low–relief mountain belt. The latter cause anomalous gravity highs along the thickened crust and the isostatic equilibrium inside the Uralides lithosphere as well as the overthrust high-metamorphic rocks. The integrated URSEIS '95 seismic experiment provides fundamentally new data revealing the lithospheric architecture of an intact Paleozoic collisional orogen that allows the construction of density models. In the Urals' lithosphere different velocity structures resolved by wide-angle seismic experiments along both the URSEIS '95- and the Troitsk profile. They can be used to constrain lithospheric density models: a first model consists of a deep subducted continental lower crust which has been highly eclogitized at depths of 60–90 km to a density of 3550 kg/m³. The second model shows a slightly eclogitized lower crust underlying the Uralide orogen with a crustal thickness of 60 km. The eclogitized lower crust causes a too-small impedance contrast to the lithospheric mantle resulting in a lack of reflectors in the area of the largest crustal thickness. Both models fit the measured gravity field. Analyzing the isostatic state of the southern Urals' lithosphere, both density models are in isostatic equilibrium.     

古尔班通古特沙漠1970-2000年代生物结皮覆盖变化研究

生物结皮是古尔班通古特沙漠主要的地表覆盖类型,也是维持其地表稳定的重要生物因子。论文利用20世纪70年代中期、80年代末期及21世纪初的遥感影像,通过生物结皮指数提取了古尔班通古特沙漠在相应时期内的生物结皮空间分布。在此基础上,分析了研究区近30年来生物结皮空间分布的变化特征;利用景观分析软件Fragstats计算了各个时期内结皮覆盖的景观指数熏并对其变化特征进行了分析。结果表明:由于新疆气候增湿、增暖明显,近30年来结皮发育良好。但由于油田开采、水利工程建设、牲畜放牧等人类活动的加强,结皮发育受到较为严重的干扰,区域内结皮斑块破碎化程度加大。     

陕北水蚀风蚀交错区生物结皮对土壤酶活性及养分含量的影响

论文以陕北水蚀风蚀交错区六道沟小流域的生物结皮为对象,研究分析了其对土壤酶活性和土壤养分特征的影响。结果表明:生物结皮对土壤酶活性和土壤养分的影响主要体现在结皮层。结皮层的土壤脲酶和过氧化氢酶活性分别为下层(0～2 cm)土壤的1.56和1.31倍,碱性磷酸酶活性提高幅度最大,为结皮下层的3.72倍;生物结皮能显著提高结皮层土壤有机质、全氮及速效氮含量(P0.05),研究中结皮层土壤有机质、全氮、速效氮含量分别为15.67 g.kg-1、0.65 g.kg-1和22.51 mg.kg-1,而其下0～2 cm层土壤则分别为5.54 g.kg-1、0.30 g.kg-1和14.6 mg.kg-1;生物结皮对土壤速效磷和速效钾的影响不明显(P0.05);生物结皮层土壤pH值为8.08,低于其下0～2 cm层土壤(pH值为8.32,P0.05)。总之,生物结皮的形成和发育可以改善表层土壤的生物化学性质,对该区植被的恢复与重建具有积极意义。     

微生物浸出低品位氧化物型镍钴矿研究新进展

微生物浸出技术是处理低品位矿石的有效措施。但目前我国主要针对硫化矿的自养微生物浸出进行研发,而对异养微生物浸出氧化型矿石研究很少。异养微生物可通过其产生的代谢产物的酸解、还原、碱解及络合作用来提取或者溶解低品位氧化物型镍钴矿中的镍、钴金属,有助于解决目前我国镍钴资源短缺及为重金属污染治理提供技术方法。本文针对低品位氧化型镍钴矿、风化壳、以及冶金渣、废电池、废催化剂等二次资源,介绍了世界镍钴资源的现状和低品位氧化物型镍钴矿的资源类型,对异养微生物浸出低品位氧化物型镍钴矿研究现状进行了剖析,指出了异养微生物冶金的主要浸矿条件和存在难题,提出了氧化物型镍钴矿微生物浸取的研究方向。