Spontaneous self-combustion of organic-rich lateglacial lake sediments after freeze-drying     

Nadine Dräger  Achim Brauer  Brian Brademann  Rik Tjallingii  Michał Słowiński  Mirosław Błaszkiewicz  Norbert Schlaak 《Journal of Paleolimnology》2016,55(2):185-194

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Revision of the Conchostracan Genus Tenuestheria from the Upper Cretaceous Lanxi Formation in Zhejiang and Its Biostratigraphic Significance in Southeast China   总被引：1，自引：0，他引：1  

LI Gang  WAN Xiaoqiao  Helmut WILLEMS  David J. BATTEN 《《地质学报》英文版》2007,81(6):925-930

The diagnosis of the conchostracan genus Tenuestheria from the Lanxi Formation in Jinhua, Zhejiang Province in Southeast China is revised following an examination of the type species under a scanning electron microscope, which revealed some morphological features on the carapace that had not been recognized previously. The importance of the Tenuestheria Fauna is considered in the context of correlation of six Turonian–Santonian formations in this region of China. The value of the Cenomanian Nemestheria and Turonian Linhaiella faunas in correlating the underlying early Late Cretaceous formations is also noted.  相似文献   

地下闭式循环地热交换发电系统简介     

周刚  李金锋  Helmut WOLFF  汤凤林 《地质科技情报》2006,25(4):105-108

为解决能源问题而提出了地下闭式循环地热交换发电系统.该系统地下部分通过全井下套管形成一个封闭系统,克服了传统地热发电和干热岩发电受地质条件制约、对环境造成危害等缺点,是一种新型的不依赖位置、环境友好的地热发电系统.采用大位移技术进行钻井,应用悬链线技术对井身剖面结构进行了优化,提出了地下连接技术要求,应用分支井和膨胀套管技术固井,设计了水泥配方并进行了相关试验,优化了载热流体,计算了有机工质朗肯循环(ORC)的发电效率.  相似文献   

A Modified Form of Mild-Slope Equation with Weakly Nonlinear Effect   总被引：6，自引：0，他引：6  

LI Ruijie  WANG Houjie Dr.  Associate Professor  Engineering College of Ocean University of Qingdao  Qingdao  P. R. China Ph. D. Candidate  Engineering College of Ocean University of Qingdao  Qingdao  P. R. China 《中国海洋工程》1999,(3)

Nonlinear effect is of importance to waves propagating from deep water to shallow water.Thenon-linearity of waves is widely discussed due to its high precision in application.But there are still someproblems in dealing with the nonlinear waves in practice.In this paper,a modified form of mild-slope equa-tion with weakly nonlinear effect is derived by use of the nonlinear dispersion relation and the steady mild-slope equation containing energy dissipation.The modified form of mild-slope equation is convenient to solvenonlinear effect of waves.The model is tested against the laboratory measurement for the case of a submergedelliptical shoal on a slope beach given by Berkhoff et al,The present numerical results are also comparedwith those obtained through linear wave theory.Better agreement is obtained as the modified mild-slope e-quation is employed.And the modified mild-slope equation can reasonably simulate the weakly nonlinear ef-fect of wave propagation from deep water to coast.  相似文献   

DARCY'S COEFFICIENT OF PERMEABILITY AS SYMMETRIC TENSOR OF SECOND RANK     

A. C. LIAKOPOULOS Dr. Eng. 《水文科学杂志》2013,58(3):41-48

Synopsis

The dynamic equation of motion that governs the laminar flow of water through soils is the empirical equation of Darcy. According to Darcy's equation the velocity of the flowing water is proportional to the hydraulic gradient under which the water is flowing, with the constant of proportionality being the coefficient of permeability. The interesting question arising is whether or not the coefficient of permeability is a scalar quantity (having only a magnitude) or a vector (having both magnitude and direction). It is proved, in the present paper, that the permeability coefficient is neither a scalar nor a vector but a symmetric tensor of second rank. The fact that the permeability tensor is symmetric gives rise to great simplifications and permits a simple graphical construction of the tensor ellipsoid. Having the tensor ellipsoid, the determination of the direction at which the water will flow under a known imposed hydraulic gradient can be found graphically. In case of isotropic soils (the permeability coefficient has the same value along any direction) the ellipsoid reduces to a sphere and the tensor becomes a scalar. In the general case of anisotropic soils the permeability tensor is an entity with nine elements, six of which are independent representing pure extension or contraction along the three principal coordinate axes, thus transforming the permeability sphere into an ellipsoid and vice versa. It should be noted that in anisotropic soils the only directions along which the flow takes place in the direction of the hydraulic gradient are those of the principal axes of the tensor ellipsoid.

Permeability tests were conducted on anisotropic sandstone samples taken at different directions with respect to rectangular coordinates. The permeability coefficient values plotted on a two-dimensional polar coordinate graph paper give rise to an ellipse substantiating therefore the tensor concept of the permeability coefficient. The graphical construction of the tensor ellipse and the use of it in order to obtain the direction of flow by knowing the direction of the hydraulic gradient is also shown.  相似文献   

A Review of the Symposium on Advanced Techniques in River Basin Management: the Trent Model Research Programme     

Dr. R. B. Painter 《水文科学杂志》2013,58(4):400-401

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TOWARDS WATER DEMAND MANAGEMENT     

Dr K. Szesztay 《水文科学杂志》2013,58(4):491-496

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Australia's great comet hunter     

Dr  Ragbir Bhathal 《Astronomy& Geophysics》2010,51(1):1.23-1.25

John Tebbutt was Australia's pre-eminent 19th-century astronomer who discovered two great comets of that century. Ragbir Bathal tells his story.  相似文献   

MinIdent: An application to the identification and classification of amphiboles     

Dr. Ronald J. Goble  Dorian G. W. Smith 《Mineralogy and Petrology》1988,38(3):213-227

Summary Amphibole data in the MinIdent database (Smith andLeibovitz, 1986) were initially entered using species names quoted in the original source. The database has been updated by reclassifying these early data using the program AMPHTAB supplied by N. M. S. Rock and by adding supplemental data from the more recent literature, with the species names again checked using AMPHTAB. Associated MinIdent mineral identification software was utilized to determine which minerals in the database most closely resemble a series of unknown specimens chemically, as expressed in the Chemical Matching Index, CM, a relative figure-of-merit. Chemical data fromMogessie and Tessadri (1982) and Hawthorne (1983) were used to check the agreement between MinIdent and AMPHTAB for the classification of 221 unknown amphiboles.With 450 amphibole analyses entered and compiled in MinIdent, the name assigned by AMPHTAB showed the highest value of CM in MinIdent for 127 of the 221 unknown amphiboles (57.5°/x) and the second highest value for another 32 (14.5%). A chemically adjacent amphibole field had the highest value of CM for 59 of the 221 unknowns (26.7%), where chemically adjacent refers to a change in one chemical parameter. The greatest discrepancy between the two programs occurred in the hornblendes, with an agreement of just 20%, although for 58% of the unknowns the species with the highest CM in MinIdent was in a chemical field adjacent to the species name assigned by AMPHTAB. In many cases the disagreement between MinIdent and AMPHTAB could be ascribed to a lack of data in MinIdent.A comparison of the two programs suggests that the assignment of a single name to an unknown amphibole by AMPHTAB with no direct indication of its reliability may be; misleading. Standard analytical errors are frequently sufficient to overlap the arbitrary boundaries between amphibole species fields. In such cases it may be preferable to use a program such as MinIdent which, rather than assigning an arbitrary amphibole name, presents a list of 20 amphiboles with the degree of similarity between them and the unknown amphibole indicated. MinIdent offers the additional benefit of allowing input of other than chemical data and bases the match between unknown and standard data upon all input data. This will become more of an advantage as instruments such as automated refractometers become available for routine use.

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Zusammenfassung Ausgangspunkt war das Amphibol-Datenmaterial (Smith und Leibovitz, 1986) mit den dort verwendeten Artnamen. Diese Basisdaten wurden vervollständigt und erneuert durch Reklassifizierung mittels des AMPHTAB Programms, ergänzt durch N. M. S. Rock, und durch Hinzufügung weiterer Daten aus der neuesten Literatur, deren Speciesnamen wiederum mit AMPHTAB überprüft wurden. Außerdem wurde eine MinIdent Mineralidentifizierungs-Software verwendet, um die Minerale zu bestimmen, die in ihrem Chemismus am ehesten einer Serie von unbekannten Amphibol-Species entsprechen, wie sie im Chemical Matching Index (CM) aufscheinen. Zur Klassifikation von 221 unbekannten Amphibolen wurden chemische Daten von Mogessie und Tessadri (1982) verwendet um die Übereinstimmung zwischen MinIdent und AMPHTAB zu überprüfen.Unter den 450 in MinIdent zusammengestellten und eingegebenen Amphibolanalysen zeigen die bei AMPHTAB angegebenen die höchsten CM Werte, nämlich 127 von 221 unbekannten Amphibolen (57,5%) und weitere 32 (14,5%) die zweithöchsten Werte. Innerhalb eines chemisch benachbarten Amphibolfeldes hatten 59 der 221 unbekannten Amphibole (26,7%) die höchsten CM Werte, wobei unter achemisch benachbart die Änderung eines chemischen Parameters zu verstehen ist. Die größten Unterschiede zwischen den beiden Programmen traten bei den Hornblenden auf. Die Übereinstimmung lag bei nur 20%, obwohl bei 58% der unbekannten Amphibole die Species mit dem höchsten CM Wert in MinIdent in ein chemisches Feld zu liegen kamen, welches zu den bei AMPHTAB angegebenen Speciesnamen eine benachbarte Position einnimmt. Die Unterschiede zwischen MinIdent und AMPHTAB könnten in vielen Fällen auf ein Fehlen von Daten in MinIdent zurükzuführen sein.Ein Vergleich beider Programme deutet an, daß die Angabe eines Einzelnamens für ein unbekanntes Amphibol im AMPHTAB Programm ohne Angaben über die Zuverlässigkeit zu Mißverständnissen führen kann. Normale analytische Fehler können bereits dazu führen, daß die Grenzen zweier willkürlicher Amphibolfelder überlappen. In derartigen Fällen emphiehlt sich die Anwendung des MinIdent Programmes, welches eben nicht einen willkürlichen Amphibolnamen angibt, sondern eine Liste von 20 Amphibolen mit dem Grad ihrer Ähnlichkeit, und einem Hinweis auf den unbekannten Amphibol. MinIdent bietet den zusätzlichen Vorteil, daß man außer chemischen auch andere Daten eingeben kann, und stellt dann sämtliche Daten des unbekannten Amphibols den Standard Daten gegenüber. Dieser Klassifizierungsvorgang wird mit der zunehmenden Routineanwendung von automatischen Refraktometern verstärkte Anwendung finden.

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Industrialisation in Fiji: Industrial structure and organisation     

Dr. Chandra Rojesh 《GeoJournal》1988,16(2):169-178

This paper analyses the significance, structure, and organisation of the manufacturing sector in Fiji, drawing on the author's earlier much larger study of industrialisation in Fiji. The latest Fijian census of industrial production (1984) and the author's 1983 survey of manufacturers in Fiji provide the main statistical basis of the study, which shows that the manufacturing sector is a moderately important component of the Fijian economy. It is dominated by resource industries, particularly food processing, but a wide range of manufacturing activities have, nonetheless, developed. There is a substantial number of small manufacturing establishments with a few large establishments, the latter, however, making an overwhelmingly important contribution to employment, gross output and value added. The market structure in the manufacturing sector is dominated by monopolies and oligopolies resulting from Fiji's small domestic market and its import substitution industrialisation strategy. There is an absence of informal sector activities in Fijian manufacturing, most firms being incorporated companies. The state has a major role as a direct producer in Fijian manufacturing. There are bound to be major changes in the manufacturing sector due to Fiji's current political crisis, but this paper does not address these because of the recency of the events and the consequent unavailability of relevant data.  相似文献