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41.
长安金矿位于哀牢山成矿带南段,是该成矿带上新近发现的又一大型金矿床。该区为哀牢山地体边缘地壳增生带,主要由深变质岩系组成,区内构造断裂发育,对岩浆活动和成矿作用有显著影响。本文总结了长安金矿的地质特征,并以该区的控矿断裂F6为主要研究目标,以地层岩性电性特征作为约束条件,分别展开了磁法、激电、瞬变电磁和大地电磁等综合物探手段的试验研究。研究结果表明,磁法对于该矿找矿效果不明显,瞬变电磁和大地电磁测深反演的电阻率低阻体,准确界定了控矿断裂F6的位置、倾向、断距以及深部延伸情况,通过激电异常可大致判断矿体的位置。所以在长安金矿区下一步的深部隐伏矿勘查中,结合瞬变电磁、激电、大地电磁等地球物理方法,辅以土壤化探异常进行约束,可以达到快速有效找矿之目的。 相似文献
42.
腕足类新科Spinochonetidae(fam.nov.)建立在宜昌地区志留系兰多维列统罗惹坪组下段中部(上埃隆阶)的Spinochonetes Rong,Xu et Yang(1974)和Spinolella(gen.nov.)两个属,以及一个属、种未定的分类单元的基础上。新科成员仅有从腹壳喙部伸出一根直的腹喙刺,这与Chonetoidea超科内的Strophochonetidae科以及Chonestrophiidae科众成员的铰合缘刺都是从腹壳铰合缘上伸出来的有着本质差别。另外,本文还对Spinochonetes以及它的属型种S.notata Rong,Xu et Yang(1974)进行重要图解和补充描述。与此同时,对Spinolella(gen.nov),以及S.minuta(gen.et sp.nov.)进行系统描述和对比。据目前所知,新科成员只分布于我国鄂西、黔东北、陕南和川北等地,属于上扬子台地的土族居民。因为Spinochonetidae(fam.nov.)属于腕足类独特的一个类型,演化快,贝体极小,保存精美,因此具有分类学、地层对比,以及恢复古环境等方面的重要意义。 相似文献
43.
Preserving coastal natural character: Court interpretations of a long‐standing New Zealand policy goal 下载免费PDF全文
Victoria Ann Froude 《New Zealand geographer》2015,71(1):45-55
New Zealand's policy goal to preserve coastal natural character was first incorporated into planning legislation in 1973 and protected area legislation in 1977. An evaluation of 100 relevant Resource Management Act Court decisions determined the Courts' interpretations of this policy goal. The Courts have repeatedly found that natural character is of nature (not culture), including natural elements, patterns, and processes. There is a continuum of naturalness from pristine indigenous ecosystems to the urban environment. A 2014 Supreme Court decision has upheld the use of environmental bottom lines for natural character and the importance of protection as part of sustainable management. 相似文献
44.
New sources of data such as ‘big data’ and computational analytics have stimulated innovative pedestrian oriented research. Current studies, however, are still limited and subjective with regard to the use of Google Street View and other online sources for environment audits or pedestrian counts because of the manual information extraction and compilation, especially for large areas. This study aims to provide future research an alternative method to conduct large scale data collection more consistently and objectively on pedestrian counts and possibly for environment audits and stimulate discussion of the use of ‘big data’ and recent computational advances for planning and design. We explore and report information needed to automatically download and assemble Google Street View images, as well as other image parameters for a wide range of analysis and visualization, and explore extracting pedestrian count data based on these images using machine vision and learning technology. The reliability tests results based on pedestrian information collected from over 200 street segments in Buffalo, NY, Washington, D.C., and Boston, MA respectively suggested that the image detection method used in this study are capable of determining the presence of pedestrian with a reasonable level of accuracy. The limitation and potential improvement of the proposed method is also discussed. 相似文献
45.
Revision of the Cenomanian echinoids deposited in the Cairo Geological Museum resulted in the erection of two new genera with two new species of regular echinoids. The first, Notatudiadema rekeibensis gen. and sp. nov. is established for specimens from the Cenomanian of Gabal El-Rekeib, southeast the Maghara massif, north Sinai to accommodate diadematoid echinoids having hemi-crenulate ambital and sub-ambital interambulacral tubercles with the adapical part of platform non-crenulate and the adoral one of same tubercle coarsely crenulate. The second is Aegyptiaris halalensis gen. and sp. nov., erected for material from the lower Cenomanian of Gabal El-Halal, northeast Sinai as an emiratiid echinoid with throughout polyporus ambulacra and extremely reduced adapical ambulacral tubercles. The functional morphology and paleobiology of these taxa are also discussed. A new family is established: family Monodiadematidae fam. nov. 相似文献
46.
《Geoforum》2015
This review offers a critical reading of the November 2014 India–U.S. trade deal that unblocked an impasse in the World Trade Organization’s (WTO) Doha round and considers what it means for the way we govern global trade. It argues that the agreement, rather than being a ‘victory’ for the developing world or a cause for celebration, may simply reinforce an unfair and problematic system of distributing trade opportunities among WTO members. It may also obscure further the need for a fundamental overhaul of the way global trade is governed. In so doing, the review speaks to broader debates about what happens when ‘rising’ powers replace established states in global institutions in the absence of wider processes of reform; and it adds to growing concerns about the increasing precariousness of least developed countries (LDCs) in international economic regimes. 相似文献
47.
We describe herein a new genus and species of Sycoracinae (Xenosycorax engeli). This new taxon is characterized, described, illustrated and its taxonomic position is discussed. This discovery is very interesting for the understanding of the evolution of this group. 相似文献
48.
A new genus and species of Scoliidae (Hymenoptera), Sinoproscolia yangshuwanziensis gen. et sp. nov., is described from the Lower Cretaceous Yixian Formation in Inner Mongolia, China and attributed to the subfamily Proscoliinae. Some characteristics, including complete crossveins 1r-rs and 2r-m in the forewing, and a free section present in almost all longitudinal veins indicate a basal position of the new genus in Proscoliinae. The presence of vein 2A suggests its atavistic origin in Sinoproscolia gen. nov. rather than a true plesiomorphy. 相似文献
49.
50.
产于贵州瓮安埃迪卡拉系陡山沱组磷块岩中的“瓮安生物群”是认识早期生命起源与演化的重要窗口。因为其特殊的磷酸盐化作用,其中的球状化石内部保存了大量精细的细胞甚至亚细胞结构,但保存这些化石的磷酸盐化作用机理尚不清楚。因此,本文采用绿藻门下团藻和空球藻为实验对象,通过改变pH、温度、氧气含量等实验条件,探索藻类在不同埋藏环境下的保存状况,为早期磷酸盐化化石的埋藏机制提供证据。实验结果显示藻类在不同实验条件下的保存潜力差距较大,相同环境下两种藻类所体现的保存潜力也不一致,但都具备足够的保存潜力;空球藻细胞在埋藏过程中出现褶皱变形,但在不同条件下的形态学差异并不明显;团藻的繁殖体形态与瓮安生物群中的一类多细胞球状化石的细胞分裂形式十分相似;早期状态一致的同种藻类不管在相同还是不同的实验条件下其个体直径大小均表现出较强的差异性。本次实验模拟自然状态下的埋藏环境,因此实验现象可能在现实埋藏过程中重现,通过实验得出以下结论:磷酸盐化的埋藏环境中藻类具备足够的保存潜力;磷酸盐化会导致生物获得自身以外的形态学信息;在不同的埋藏学环境下保存的磷酸盐化球状化石的直径大小会有差异;胚胎状化石与磷酸盐化的现生藻类... 相似文献