全文获取类型
收费全文 | 357篇 |
免费 | 11篇 |
专业分类
368篇 |
出版年
2019年 | 9篇 |
2018年 | 11篇 |
2017年 | 10篇 |
2016年 | 12篇 |
2015年 | 7篇 |
2014年 | 4篇 |
2013年 | 104篇 |
2012年 | 7篇 |
2011年 | 4篇 |
2010年 | 12篇 |
2009年 | 10篇 |
2008年 | 9篇 |
2007年 | 11篇 |
2006年 | 9篇 |
2005年 | 4篇 |
2004年 | 5篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 3篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 8篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1986年 | 3篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 9篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1972年 | 4篇 |
1970年 | 6篇 |
1968年 | 2篇 |
1965年 | 1篇 |
1964年 | 2篇 |
1955年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有368条查询结果,搜索用时 0 毫秒
1.
Kenneth Maddock 《Oceania; a journal devoted to the study of the native peoples of Australia, New Guinea, and the Islands of the Pacific》1988,58(4):305-310
Australia is on the brink of a recession, and we have platinum, palladium and 350,000 ozs of gold locked up in Coronation Hill but we cannot go ahead and mine it because, all of a sudden, it has become a sacred site. It was not a sacred site fifty years ago. Barry Coulter, Treasurer of the Northern Territory, 27/8/86 相似文献
2.
We develop a new conceptual approach to locating inspection stations for hazardous vehicles, prevention, and compare it to the previous, punitive, philosophy of the flow-capturing location model. We implement this preventive protection philosophy with a new mixed integer program that maximizes hazard avoidance by locating a number of inspection stations to detect and remove hazardous vehicles as early in their trips as possible. We test the model's performance and analyze the spatial characteristics of solutions simulating several potential applications. Our computations demonstrate that a relaxed integer-linear program is overly demanding computationally and that a simple greedy heuristic lacks robustness. We suggest further approaches to developing more powerful and efficient solution methods. 相似文献
3.
ABSTRACT. This paper proposes a new method for estimating a monthly regional production model. The technique involves treating the region's monthly industrial output as a latent variable, which is in turn a function of capital (prosed by energy usage) and labor inputs. Annual observations on regional value added correspond to the summation of the unobservable monthly series over the 12 months, while changes in the national Industrial Production index help infer the series' month-to-month fluctuations. The model is estimated using the Kalman filter and the method of maximum likelihood. The estimates are used to compute monthly indices of regional value added for 15 individual 2-digit industries, and for the aggregate manufacturing sector in the Seventh Federal Reserve District. In a comparison of out-of-sample forecasting accuracy, the mixed-frequency model outperforms both the traditional parametric Cobb-Douglas and nonparametric Atlanta methods over the 1988–89 forecasting horizon. 相似文献
4.
5.
Kevin D. Ingram Kenneth E. Daugherty James L. Marshall 《Journal of archaeological science》1993,20(6)
Several samples of pyramids from Giza were obtained. The samples were analysed by scanning electron microscopy, electron diffraction by X-rays, powder X-ray diffraction, inductively coupled plasmography, Fourier-transform infrared spectroscopy and other techniques. Some scientists who have recently studied the pyramids have suggested that the pyramids were poured into place, stone by stone. The prevailing theory among Egyptologists is, of course, that the pyramids were built from blocks of natural stone. All of the results obtained during this study directly support the concept that the pyramids are made of limestone and are not cementitious in nature. 相似文献
6.
7.
8.
9.
10.