共查询到20条相似文献，搜索用时 312 毫秒
1.
2.
Wang Jingtao 《岩土力学》1989,10(3):6-12
This paper is written for the 30th anniversary celebration of the founding of our institute . the development and achievements of rock dynamics in the past 30 years in our institute are summarized briefly. The prospect for further development of rock dynamics in our institute, including some opinions and suggestions about the research topics to study, are also made in this paper. 相似文献
3.
We develop an improved methodology for modelling the relationship between mean track length, temperature, and time in fission track annealing experiments. We consider “fanning Arrhenius” models, in which contours of constant mean length on an Arrhenius plot are straight lines meeting at a common point. Features of our approach are explicit use of subject matter knowledge, treating mean length as the response variable, modelling of the mean-variance relationship with two components of variance, improved modelling of the control sample, and using information from experiments in which no tracks are seen.
This approach overcomes several weaknesses in previous models and provides a robust six parameter model that is widely applicable. Estimation is via direct maximum likelihood which can be implemented using a standard numerical optimisation package. Because the model is highly nonlinear, some reparameterisations are needed to achieve stable estimation and calculation of precisions. Experience suggests that precisions are more convincingly estimated from profile log-likelihood functions than from the information matrix.
We apply our method to the B-5 and Sr fluorapatite data of Crowley et al. (1991) and obtain well-fitting models in both cases. For the B-5 fluorapatite, our model exhibits less fanning than that of Crowley et al. (1991), although fitted mean values above 12 μm are fairly similar. However, predictions can be different, particularly for heavy annealing at geological time scales, where our model is less retentive. In addition, the refined error structure of our model results in tighter prediction errors, and has components of error that are easier to verify or modify. For the Sr fluorapatite, our fitted model for mean lengths does not differ greatly from that of Crowley et al. (1991), but our error structure is quite different. 相似文献
4.
Twenty-four geochemical reference samples have been analysed far barium using the stable isotope dilution technique. These include five CRPG, ten ANRT, six Nimroc and two CCRMP samples together with the Tonalite from Tanzania, Duplicate analyses have been made in each case and our values for barium are believed to be accurate to approximately 3 %. In general, our results are in good agreement with the published data except for Nimroc samples where our data are consistently lower than the presently accepted values. No evidence of sample inhomogeneities was observed in the present work. 相似文献
5.
地质环境与城市发展研究综述 总被引：8，自引：0，他引：8
该文概述了城市地质环境与城市发展国内外研究现状,指出了我国城市工程地质工作存在的问题,论证了地质环境与城市发展中主要问题的解决途径,提出了地质环境与城市发展研究与工作的一些建议。论文还介绍了与地质环境与城市发展密切相关的我国工程地质专业设置现状与发展趋势。 相似文献
6.
Modelling is an indispensable tool in geochemical engineering in predicting the outcome of our intended interferences in geochemical systems. Because such systems are highly complex, investigation by means of designed experiment can only apply to subsystems and processes. Models too can only capture a partial, simplified image of the true system. Conceptual models play a vital role. Advantages of the use of models are, a.o., better testing of our understanding of geochemical processes, better formulation of this understanding, and better prediction of the outcome of our conjectures. Examples from hydrogeochemistry are discussed to demonstrate this. 相似文献
7.
煤层气是一种洁净的新能源，我国煤层气储量十分丰富，开发煤层气的方法有地面钻井开采和井巷开采两种，其中井巷开采方法适用于我国许多矿区。本文分析了我国煤层气藏的地质条件，提出了综合采煤采气要求布置井下巷道，改进传统瓦斯抽放工艺开采煤层气的井巷全量开采法，并对本方法进行了理论和实践上的论证。 相似文献
8.
王承祺 《华东地质学院学报》1987,(1)
本文提出的九种类型金矿床,是目前我国最主要的普查-勘探对象,其中特别详细介绍了卡林式金矿床、团结构式金矿床、焦家式金矿床和东风山式金矿床。对于分布广、数量多,与有色金属伴生的金(银)矿床,着重指出了其利用的前景。这样,可使一矿变多矿、小矿变大矿,甚至遍布全国的有色金属矿山开采的废石、废渣也有可能采出金(银)。对全国各省(区)金的主要来源的砂金矿床和脉金矿床,也给予很高评价与重视。本文还就找金的方法,提出了地质-物探-化探-遥感综合方法,还介绍了国外对低品位金矿常用的氰化物溶液堆浸处理法,提取金和在水中鉴定金痕量的超灵敏度找矿法。 相似文献
9.
滨海城市环境工程地质问题发育特点分析 总被引：1，自引：0，他引：1
李相然 《水文地质工程地质》1998,25(2):19-21
本文分析了我国滨海城市环境工程地质问题的主要类型,研究了环境工程地质问题的发育特点。 相似文献
10.
我国城乡统筹发展正处在不断探索发展的阶段,该文在分析英国、美国、日本、韩国、印度、挪威城乡统筹发展经验的基础上,参考这些国家在缓解城乡矛盾时政府主导、统一规划等积极做法,结合我国的实际情况,提出了促进我国城乡统筹发展的对策建议。 相似文献
11.
Chen Jiawei Bao Zhengyu Mei YupingFaculty of Earth Sciences China University of Geosciences Wuhan 《中国地质大学学报(英文版)》2001,12(3)
Ｈｅａｔｅｆｆｅｃｔｏｃｃｕｒｓｉｎｍａｎｙｐｈｙｓｉｃａｌａｎｄｃｈｅｍｉｃａｌｒｅａｃｔｉｏｎｐｒｏｃｅｓｓｅｓｉｎｎａｔｕｒｅ .Ｍｅａｓｕｒｉｎｇｔｈｅｈｅａｔａｃｃｕｒａｔｅｌｙｉｎｖｉｅｗｏｆｅｎｅｒｇｙｉｓａｆｕｎｄａｍｅｎｔａｌｔｏｏｌｆｏｒｓｔｕｄｙｉｎｇｐｈｙｓｉｃａｌａｎｄｃｈｅｍｉｃａｌｒｅａｃｔｉｏｎｓｙｓｔｅｍ .Ｃａｌｏｒｉｍｅｔｅｒｉｓａｄｉｒｅｃｔａｐｐｒｏａｃｈｔｏｈｅａｔｍｅａ ｓｕｒｅｍｅｎｔｓ.Ｂａｓｅｄｏｎｔｈｉｓ ,ｗｅｃａｎｅｘｐｌｏｒｅｍａｔｅｒｉａｌｔ… 相似文献
12.
本文简述了我国桩工行业的发展现状及主要问题，阐述了我国桩工行业实现可持续发展的指导思想和主要途径，提出了有效支持桩工行业发展的绿色制造实施系统。 相似文献
13.
A conceptual investigation of the ontological commensurability of spatial data infrastructures among different cultures 总被引：1，自引：0，他引：1
David J. Saab 《Earth Science Informatics》2009,2(4):283-297
Humans think and communicate in very flexible and schematic ways, and a Spatial Data Infrastructure (SDI) for the Amazon and
associated information system ontologies should reflect this flexibility and the adaptive nature of human cognition in order
to achieve semantic interoperability. In this paper I offer a conceptual investigation of SDI and explore the nature of cultural
schemas as expressions of indigenous ontologies and the challenges of semantic interoperability across cultures. Cultural
schemas are, in essence, our ontologies, but they are markedly different than classical formal ontologies. They shape our
ontological commitments to what exists in the world as well as the ways in which we approach and engage the world. And while
they help structure our understanding of the world in which we are embedded, they are associative and flexible. They help
to focus our attention to particular details of our experiences and give them salience, yet they cannot be simply reduced
to a series of extracted features. They allow us to make meaning of the contextualized, cultural experience in which we are
always immersed. An SDI is a shared social-technological-informational structure that, if it is to be useful and successful
for sustainability in the Amazon, must incorporate and use indigenous cultural schemas. Indigenous communities must have the
ability to contribute to the collection of geospatial data and their contributions recognized as legitimate forms of knowledge.
In order for the SDI to work, it must recognize the larger cultural landscape to which cultural schemas can connect to the
ready-to-hand elements of salient cultural experiences. 相似文献
14.
李相然 《水文地质工程地质》1999,26(2):42-44
滨海城市是我国经济最发达的地区,近年来经济与城市建设均得到迅速发展,城市土地开发力度加大,由此引起的环境工程地质问题也日趋严重,本文分析了我国滨海城市地区区域地质环境和人类工程经济活动的地域差异,研究了滨海城市环境工程地质问题的主要类型,并提出了滨海城市环境工程地质问题的地域分异规律。 相似文献
15.
中国周边国家金属矿产资源调查与合作潜力分析 总被引：2，自引：0，他引：2
中国是矿产资源大国,种类齐全,总量较大,但优势金属矿种多为一般矿产,主要战略性矿产的储量严重偏低,研究中国周边国家资源的供给能力与合作潜力分析对我国经济可持续发展意义重大. 相似文献
16.
乌兹别克斯坦的矿产资源与投资前景—随中国科学家代表团访问乌兹别克斯坦考察报告之一 总被引：3，自引：0，他引：3
介绍了乌兹别克斯坦共和国的地质构造背景，已探明的和潜在的矿产资源，投资环境及可供我国利用的矿产资源。乌兹别克斯坦共和国是我国的近邻，其金，铀，钾盐，银，铜是乌兹别克斯坦的优势和矿产资源，尤其是金和铀的储量与产量在世界上占有重要的地位，应当在我国矿产资源的全球战略中占据它应有的位置。 相似文献
17.
就城市设计中历史文化保护问题展开了较全面的阐述和探讨,广泛引用、借鉴西方的先进理论与实践经验,并提出探索我国历史文化城市中的城市设计与景观环境保护的一些相关思考,以对当前我国经济快速发展进期城市历史文化保护的紧迫局面有所裨益。 相似文献
18.
We have derived the normal spectral energy distributions for those early-type subgiants, giants, and supergiants that were not investigated in our earlier studies, which were in most cases also not included in the studies of Sviderskiene. Color indices computed using our normal energy distributions are in good agreement with normal colors derived from observations in the Vilnius photometric system. The reliability of our distribution curves is also demonstrated by comparisons of observed and computed (W-B)-(B-V) two-color diagrams in the WBVR system. Normal color indices for the photometric WBVR system are derived. 相似文献
19.
D. I. Novikov A. G. Doroshkevich I. D. Novikov A. A. Shatskii 《Astronomy Reports》2009,53(12):1079-1085
Physical processes arising when an impermeable wormhole is irradiated by self-gravitating, exotic radiation are considered.
It is shown that, in this case, the conditions required for the passage of signals fromanother universe into our own arise
only in our Universe, whereas signals cannot pass through the wormhole in the opposite direction. Such wormholes are called
semi-permeable. The stability of a static wormhole filled with radial magnetic field and exotic dust with a negative energy
density is also considered. 相似文献