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11.
J. A. J. Gowlett 《Journal of World Prehistory》1987,1(2):127-170
Accelerator mass spectrometry (AMS) allows radiocarbon dating to be carried out by direct counting of14C atoms, rather than the conventional counting of radioactive disintegrations. The result is that samples up to 1000 times smaller can be handled. The approach was tested in principle by 1977 and for archaeological operation by 1983. More than 2000 samples per year are now being dated worldwide. The machines can now operate to about ± 80 years or better. Dates older than 40,000 years have not yet been achieved, but the ability to use small samples has already had considerable impact on dating the period 10,000–30,000 years ago. Bone is an ideal material for the new technique, since amino acids can normally be isolated and purified from gram-size samples. Studies of the origins of domestication are aided by the dating of individual grains and seeds. Because small samples can be mobile in the soil, careful sample selection strategies and procedures are required. The full impact of the technique can be assessed only through the rapid and comprehensive publication of archaeological results. 相似文献
12.
Federico Lugli 《International Journal of Osteoarchaeology》2019,29(6):1109-1111
The in‐situ Sr isotope determination of low‐Sr bioapatites is challenging and requires monitoring several interferences, among others, Ar‐CaPO. In particular, the analysis of human bones and teeth has revealed several pitfalls, which affect the ability to obtain accurate results. In this commentary, I review the data from the paper of Meijer et al. (2019), trying to address some accuracy issues arising, in my opinion, from polyatomic interferences. After a tentative calibration of their data, using the 1/88Sr signal (V−1) as a proxy of the Sr content, the enamel specimens (enamel Ar‐CaPO corrected 87Sr/86Sr ratio = 0.7078 ± 0.0032; mean ± 2σ) are closer to the likely local bioavailable Sr (bone Ar‐CaPO corrected 87Sr/86Sr ratio = 0.7071 ± 0.0011; mean ± 2σ). 相似文献
13.
The studies on the finishing technique of the stone monuments in Persepolis (Iran) are part of the archaeological project jointly launched in 2008 by Iran and Italy, named ‘From Palace to Town’. The first experimental results, obtained on a very limited number of samples, revealed that the Achaemenid builders and sculptors used a white pigment, a kind of bone white, calcium fluorapatite, obtained by burning animal bones, to hide the dark grey colour of the stone. In order to verify these unexpected results, a new campaign was implemented to analyse a much larger number of samples. XRF spectrometry, a non‐destructive technique, was used and the experimental results were further elaborated by PCA. The presence of a white superficial layer was confirmed, and the use of fluorapatite was confirmed as well, but only on monuments attributed to the Xerxes period or later, while in the earlier monuments the white layer was obtained using gypsum. 相似文献
14.
《International Journal of Osteoarchaeology》2017,27(2):180-191
Body mass is a key biometric that is useful in interpreting many aspects of an animal's life history. For many species, including dogs and wolves, methods for estimating body mass are not well developed. This paper assesses the utility of using limb dimensions to predict body mass in dogs and North American wolves. Regression analyses are utilized here to explore the correlations between limb dimensions and body masses of modern dogs and wolves, all of known body mass at death. These analyses reveal that a number of limb end dimensions are correlated with body mass in both dogs and wolves. Regression formulae generated through the analyses appear to allow body masses to be predicted with relatively small margins of error, often less than 10%. Formulae are calculated for groups with and without juveniles. In some cases, the dimensions of the juvenile specimens plot distinctly from those of adults, indicating that regression formulae specifically for juvenile canids may be needed. The strength of the limb dimension correlations is then compared with that of regression formulae for dog and wolf cranio‐mandibular dimensions. For the dogs, the cranio‐mandibular dimensions appear to slightly out‐perform the limb element dimensions in predicting body mass. The wolf limb dimensions, however, always appear to provide better predictions of body mass than do the skull dimensions. The newly developed regression formulae are applied to several Middle Holocene dog skeletons from Siberia for which previous body mass estimates are available, the latter based on cranial dimensions. These two sets of estimates are then compared. The overall results of our study indicate the need for further research, particularly with larger sample sizes, including more juvenile specimens. We also argue that work on body size estimation in single dog breeds may be warranted in some cases. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
15.
A sliding mode control theory is presented to control the response of building frames to predominant frequency components of the random ground motions. The control algorithm is derived based on a sliding surface which is a function of a state vector containing the structural displacements and velocities and variables that dictate the predominant frequency components of the excitation. Three control mechanisms are employed to control the response of the building frame namely, (1) active mass damper (AMD) placed at the top storey of the building, (2) an actuator placed at a storey level and, (3) an actuator placed at a storey level along with a tuned mass damper (TMD) situated at the top storey level. Responses obtained by the proposed control strategy are compared with those obtained by the linear feedback and feedforward-feedback control strategies (conventional control strategies). Also, they are compared with those obtained by the sliding mode control strategy that considers in its state vector only structural displacements and velocities. It is shown that the proposed control strategy generally performs better than other control strategies in the higher range of control forces. For the lower range of control forces, conventional control strategies are more effective. 相似文献
16.
Nindyo Sasongko 《Political Theology》2013,14(3):280-295
ABSTRACTThis study demonstrates how ignorance works in the Indonesian massacres of 1965–1966. This atrocity, which claimed roughly five hundred thousand lives, is one of the most forgotten human tragedies of the twentieth century. For many years, the massacres were hidden from public view. Ignorance was reinforced by the New Order under the presidency of Suharto. Drawing on contemporary political philosophers’ studies on the epistemology of ignorance, I contend that ignorance, like knowledge, has structures, criteria, and practices. Ignorance, thus, is not merely a “lack of knowledge” or a state of not knowing, but epistemic and political. By appropriating the epistemology of ignorance, I seek to show how the Indonesian people remember the historical wrongs and how Christian theology provides resources for right remembrance. To confront the epistemic ignorance of the Indonesian mass killings, I argue that the churches must assert their identity as the community of memory and lament. 相似文献
17.
The effect of skeletal exposure in a marine environment is an area of taphonomy that has been little investigated at the microscopic level. Understanding the peri‐mortem and subsequent post mortem history of deposition and/or redeposition is extremely important for event reconstruction and to identify deliberate or accidental redeposition. The material used for this study comes primarily from the Mary Rose shipwreck (a marine mass fatality dated AD 1545), and forensic material recovered from marine, lacustrine and terrestrial contexts is retrospectively referenced. Work presented here outlines a definitive type of marine exposure seen in temperate shallow off‐shore and intertidal marine contexts, and illustrates how it may be differentially identified from terrestrial deposition and exposure. Furthermore, the effects of rapid deposition on skeletal remains have been documented, and results indicate that marine organism fouling activity can be fully inhibited by rapid deposition of sediment. The responsible organism itself remains unidentified, but produces tunnels which are peripheral in their distribution and maintain fixed dimensions and morphology and are here associated with marine exposure. This type of microstructural change is unique and is not found in terrestrial or freshwater contexts. The study demonstrates a taphonomic microstructural change to bone and teeth which may be identified microscopically and interpreted as evidence of marine exposure. Secondarily, the history of depositional exposure between the two main Tudor layers has provided a new level of detail concerning exposure and site formation processes. The earliest Tudor layer formed rapidly over a period of months and contained no evidence of microstructural tunnelling, whereas microstructural tunnelling was seen exclusively in the second Tudor layer, formed over a period of decades, a period during which the ship's hull collapsed and a more open marine environment dominated. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
18.
19.
Yulia Karpova 《European Review of History》2013,20(4):627-647
This article investigates the background of Soviet industrial design in Soviet art theory. Instead of considering design's interconnection with technology and science, or with consumption and everyday life, the author traces its conceptualisation as a new artistic phenomenon. Using archival records of professional discussions, polemical articles in the art press and design projects, the author looks at how industrial design was incorporated into the Soviet order of things. She concludes that accommodation of the Western model was the way to reform the system of socialism from inside, typical for the Soviet intelligentsia of the 1960s. 相似文献
20.
美国学术界一般认为,从三K党组织成立肇始,共经历三次连续的运动。第三次三K党运动开始于二战结束,持续至今。为了更加有效地迷惑民众,这一时期三K党采取的手段之一就是革新了该组织的宣传方略,不遗余力地利用美国当代大众传媒来宣传和标榜自己,并完成了由印刷媒体到电子媒体的转变。由于大众传媒和大众文化的密切关系,这种大众传媒方略直接影响到美国大众文化的变异,导致美国当代大众文化掺杂着三K党所宣扬的以白人种族主义为核心的消极成分,致使美国社会与文化的重构与异化。美国民众尤其是青年群体,深受此种文化理念和认知的麻痹与毒害:美国当代社会种族主义思潮的泛滥、白人至上主义运动持续、仇恨犯罪率的提升、暴力文化形式的盛行等现象便是例证。第三次三K党运动的大众传媒方略以及大众文化异化极具隐蔽性,由此导致的危害亦不容低估。 相似文献