我国超声地震模型试验的理论研究与实践   总被引：1，自引：0，他引：1       下载免费PDF全文

孙进忠  郭铁栓  唐文榜  赵鸿儒 《地球物理学报》1997,40(Z1):266-274

超声地震模型试验是地球物理模拟研究的重要手段之一，50年代后期，我国开始了超声地震模型试验的研究实践，在40多年的发展历程中，我国的超声地震模型试验在方法理论、研究实践和工程应用上都得到长足的发展，取得了丰硕的成果，成为我国地球物理学研究中的一个重要组成部分．  相似文献   

硅岩研究的进展   总被引：11，自引：1，他引：11  

唐世荣 《地球科学进展》1994,9(6):71-75

回顾了国外硅岩的研究历史，概述了当今的研究现状和未来的发展趋势，并与我国同一领域的研究状况作了对比分析，提出了改变国内硅岩研究落后现状的几点建议。  相似文献   

Cretaceous amber inclusions of Spain and Myanmar demonstrate early diversification and wide dispersal of Cephenniitae (Coleoptera: Staphylinidae: Scydmaeninae)     

《Cretaceous Research》2016

The taxonomic status of previously misplaced species of an ant-like stone beetle from Spanish amber (Albian) is clarified. Specimens of Kachinus magnificus (originally placed as incertae sedis within Scydmaenitae) were re-examined and their characters were found different from those of the type species of Kachinus from Myanmar amber. Consequently, Archeutheia gen. nov. is proposed to accommodate the Spanish species, resulting in Archeutheia magnifica comb. nov. Moreover, in a comprehensive phylogenetic analysis Archeutheia was placed as a sister group to extant Eutheia, within the tribe Eutheiini of Cephenniitae. A specimen of an undetermined genus from Myanmar amber clearly belonging in Cephenniini is also recorded. Both taxa represent the first definite Cretaceous Cephenniitae, a supertribe whose recent members are distributed on all continents but are especially diverse in the Oriental and East Palaearctic regions. This finding demonstrates a diversification of two presently most species-rich tribes of Cephenniitae already in Early Cretaceous. Archeutheia is strikingly similar to the extant species of Eutheia and Veraphis, showing male dimorphic characters (modified protrochanters) and antennal cavities characteristic of Palaearctic Eutheiini. This fact suggests a long morphological stability in the supertribe. A previously proposed hypothesis of an early presence of the Cephenniitae in the Northern Hemisphere is for the first time supported by the fossil record, and the palaeolocalities (western Europe and Southeast Asia) demonstrate a wide distribution of Cephenniitae in the Cretaceous and an early split of its ancestral lineage.  相似文献   

A densely feathered ornithomimid (Dinosauria: Theropoda) from the Upper Cretaceous Dinosaur Park Formation,Alberta, Canada     

《Cretaceous Research》2016

A recently discovered articulated partial skeleton of Ornithomimus from the Upper Cretaceous Dinosaur Park Formation of Alberta, Canada is remarkable in the extent and quality of preservation of integumentary structures including feathers. It is the first ornithomimid to preserve a tail bearing extensive plumaceous feathers that are slightly more elongate in comparison to those present on the remainder of the body. However, the underside of the tail and the hind limb distal to the middle of the femur appear devoid of plumage. Overall, the plumage pattern in Ornithomimus is similar to that of Struthio camelus (ostrich) and other large palaeognaths, indicating a probable function in thermoregulation. The specimen also preserves the body outline around the legs, including a skin contour anterior to the femur, analogous to skin webs in extant birds. Whereas the knee web of birds bridges the knee to the abdomen, in Ornithomimus it spans from the mid-femoral shaft to the abdomen, and is herein referred to as an anterior femoral web. This is the first report of such soft tissue structures in non-avian theropods. It may indicate that the resting position of the femur was positioned more anteroventrally in ornithomimids than in most theropods, and in that sense may have been transitional to the situation in modern birds.  相似文献   

Societal Responsibility and Development Trends of Global Soil Studies and the Provisions for China: Lessons from the Status of the 《World’s Soil Resources Report》     

Zhang Xuhui  Shao Qianqian  Ding Yuanjun  Cheng Kun  Bian Rongjun  Liu Xiaoyu  Zheng Jufeng  Li Lianqing  Pan Genxing 《地球科学进展》2016,31(10):1012-1020

2015 is the International Year of Soil (IYS) adopted by the 378th Congress of the United Nations. The Status of the World’s Soil Resources was released by the Food and Agriculture Organization of the United Nations, which was the policy report about the status of the world soil resources for the first time. The universal values of the global community were strengthened by the challenges for the global society from the risk and safety of the change of soil quality, functions, services and soil health. One third of the world soil resources were suffering serious degradation, which could affect the food security in the future, regional development and local conflicts in the report. The major task of the global monitoring, regulation and management of the world soil resources and the social responsibility of supporting the sustainable soil management by education, research and technology development were highlighted. The social responsibility and global development trends of soil science and management strategies were discussed by the keywords, the distribution of contributing authors and the citation of the references, as well as the main contents of the report. The keywords distribution of the report showed that the focus of the soil research included the change of soil quality, processes, functions and services induced by the natural driving forces, human’s activity and soil degradation, as well as the hotspots covered soil carbon/nitrogen-water-biological pool and distribution related with the biogeochemistry, global climate change and ecosystem functions and human health. The number and structure of the cited papers showed that the integration research based on the mega-data analysis were the prominent development trend of the soil science. The geographic distribution of all the contributing authors showed that dominant discourse of the global soil science were grasped by the developed countries including Europe and the United States, China had just limited effects on the global soil science. It is urgent to promote China’s soil science research and the services for global society.  相似文献   

河口学调查研究的近期进展     

吴崇泽 《海洋科学进展》1992,(2)

本文从河口学的调查技术和理论研究两方面.对国外河口学调查研究近况进行了阐述,并在此基础上提出当前发展的特点,即基础理论研究获得突破性进展;广泛采用新技术;注意研究方法的改进和多学科合作,进行综合研究,共同解决问题。  相似文献   

生物海洋学的研究状况     

李永祺  吴宝铃 《海洋科学进展》1991,(4)

本文阐述了生物海洋学的内容及其研究状况。根据我国沿海特点,建议我国今后对生物海洋学研究的重点是:1.对不同水域初级生产力的研究。2.对沿海小型底栖生物在海洋生态系统能流和物质循环中的作用研究。3.河口,有代表性海域可溶性有机物(DOM)、颗粒有机物(POM)的来源、数量分布、化学组成,以及在海洋食物链的作用和鱼虾产卵场变动关系的研究。4.沿海养殖环境生原要素循环、环境容量及病害发生的环境研究。5.海洋生物对重要有机污染物和海藻毒素的吸收、富集、代谢、在食物链传递,以及生态影响和生态监测研究。6.沿海植物性碎屑向近海输运,及其在食物链中的作用研究。7.浮游生物的群集、支配群集因素,以及和渔业关系的研究。8.选择代表性海域开展物质通量的研究。  相似文献   

铰接式浮标性能研究     

冯伯俊  黄国樑  刘天威  龚骅 《海洋工程》1994,(4)

铰接式浮标作为一种新型助航标志越来越受到海监部门的欢迎。铰接式浮标具有良好的水动力性能，在风流中静倾角及在波浪中摇摆角都较小，而且定位准确。本文对铰接式浮标的结构及其水动力性能计算方法作了介绍，并在国家重点实验室──海洋工程实验室作了系列试验，得出一些有益的结果，为优化设计提供了依据。  相似文献   

Catchment area‐based evaluation of the AMC‐dependent SCS‐CN‐based rainfall–runoff models     

S. K. Mishra  M. K. Jain  R. P. Pandey  V. P. Singh 《水文研究》2005,19(14):2701-2718

Using a large set of rainfall–runoff data from 234 watersheds in the USA, a catchment area‐based evaluation of the modified version of the Mishra and Singh (2002a) model was performed. The model is based on the Soil Conservation Service Curve Number (SCS‐CN) methodology and incorporates the antecedent moisture in computation of direct surface runoff. Comparison with the existing SCS‐CN method showed that the modified version performed better than did the existing one on the data of all seven area‐based groups of watersheds ranging from 0·01 to 310·3 km². Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Generating the evidence for marine fisheries policy and management     

John Holmes  John Lock 《Marine Policy》2010

The uptake of research in marine fisheries management and policy making depends on how effectively fisheries managers, researchers and scientific advisers communicate the needs for evidence, and the results and policy implications of research. The MariFish network of the major European funders of marine fisheries has therefore undertaken a study of current practices relating to communication of research needs and results, identifying strengths and weaknesses, and consequently how two-way communications, and hence the effectiveness of generating evidence for marine fisheries policy making and management, can be improved. Conclusions and recommendations for ‘good practice’ include the importance of building good relationships and trust between researchers and fisheries managers, the need for fisheries ministries to have sufficient inhouse scientific capacity to act as ‘intelligent customers’, and the key role of interpreters of research whose skills and career paths need to be carefully developed.  相似文献