全文获取类型
收费全文 | 1307篇 |
免费 | 0篇 |
学科分类
工业技术 | 1307篇 |
出版年
2021年 | 3篇 |
2019年 | 3篇 |
2017年 | 2篇 |
2016年 | 5篇 |
2015年 | 4篇 |
2014年 | 2篇 |
2013年 | 31篇 |
2012年 | 17篇 |
2011年 | 13篇 |
2010年 | 14篇 |
2009年 | 9篇 |
2008年 | 13篇 |
2007年 | 9篇 |
2006年 | 7篇 |
2005年 | 7篇 |
2004年 | 5篇 |
2003年 | 15篇 |
2002年 | 7篇 |
2001年 | 8篇 |
2000年 | 13篇 |
1999年 | 33篇 |
1998年 | 277篇 |
1997年 | 165篇 |
1996年 | 114篇 |
1995年 | 75篇 |
1994年 | 59篇 |
1993年 | 56篇 |
1992年 | 15篇 |
1991年 | 16篇 |
1990年 | 19篇 |
1989年 | 13篇 |
1988年 | 16篇 |
1987年 | 19篇 |
1986年 | 17篇 |
1985年 | 24篇 |
1984年 | 11篇 |
1983年 | 7篇 |
1982年 | 6篇 |
1981年 | 14篇 |
1980年 | 13篇 |
1979年 | 4篇 |
1978年 | 15篇 |
1977年 | 30篇 |
1976年 | 73篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1968年 | 4篇 |
1967年 | 5篇 |
1954年 | 2篇 |
排序方式: 共有1307条查询结果,搜索用时 0 毫秒
1.
2.
3.
M Leach 《Canadian Metallurgical Quarterly》1997,93(22):52-55
We are continually expanding our knowledge of JCA and establishing our understanding on an ever-increasing knowledge base encompassing immunology, immunogenetics, physiology, psychology and sociology. The causes and treatment of this condition are multifactoral and no one discipline can hope to embrace all of them. Nurses, particularly those with rheumatological and/or paediatric expertise, are uniquely placed to provide the link between patient, the family and health care team and thus to coordinate treatment and ensure that care meets the needs of youngsters with JCA and their families. 相似文献
4.
Osteomyelitis in uncommon locations can present unusual diagnostic difficulties. A patient with primary sternal osteomyelitis who presented with pain over the right supraclavicular area and a radiologic picture of a pleural-based right upper lung mass is discussed. A triple-phase bone scan was consistent with the diagnosis, and a needle aspiration of the mass revealed a staphylococcal abscess. Percutaneous drainage of the contiguous abscess and a prolonged course of antibiotic therapy cured the infection. 相似文献
5.
Gerald Leach 《Energy Policy》1991,19(10):918-925
The UK differs from may other industrialized nations in that its carbon dioxide (CO2) emissions from energy use have declined in recent years despite relatively rapid economic growth. In all sectors but transport, substantial reductions have already occurred in the level of carbon emissions per unit of GDP output. At the same time, a number of official and unofficial studies have pointed out that the UK has one of the largest remaining potentials amongst comparable industrialized countries for achieving further CO2 reductions through the implementation of cost-effective energy efficiency and fuel switching measures. This paper discusses past and present patterns of energy use and carbons emissions in the UK. The analysis then examines historical trends in UK energy policy and presents policy options for further reducing the UK's energy-use and carbon emissions in the future. 相似文献
6.
7.
8.
An outline of the characteristics of PEEK and the versatility of its compositional forms (micro and macro composites) are given to illustrate its wide potential for success in engineering applications. Although it is necessary to have particular tabulations of mechanical properties for engineering design, these are seldom available and consequently it is argued that an understanding of stiffness, toughness and strength properties are required to fully exploit available manufacturer's data and thus develop the full potential of PEEK and its composites. Stiffness characteristics are considered in terms of a modulus function which is dependent on time under load and temperature. In its composite forms, whether reinforced with short or continuous fibres, stiffness anistropy can be both considerable and complex, but some empirical ground-rules are apparent. For continuous fibre composites even in the form of complex lay-ups, it is also possible to attempt some stiffness prediction from certain pseudo-elastic constants. Toughness of PEEK and its composites is described in terms of both comparative and intrinsic properties. Instrumented falling weight impact data, particularly as a function of temperature enable some insight into ductile-brittle transitions for the unreinforced material, but crack initiation and crack propagation processes for the various fibre reinforced forms. Intrinsic toughness is described in terms of linear elastic fracture mechanics theory. Strength properties are described for static and dynamic loading configurations. In particular, PEEK and its composites are evaluated for increasing test severities for strength characteristics; stress concentration, loading form and test temperature are considered. 相似文献
9.
D Jacob-Wilk EE Goldschmidt J Riov A Sadka D Holland 《Canadian Metallurgical Quarterly》1997,35(5):661-666
In response to a light pulse, hamsters normally generate phase advances that are positively correlated with the length of their circadian period (tau). To determine whether this is a general property of the phase-shifting oscillator, the present study looked for a correlation between tau and phase-advance size not only for photic but also for nonphotic shifts. Syrian hamsters, Mesocricetus auratus, were entrained to light-dark cycles with a periodicity of either 23.67 h (the short-T group) or 24.33 h (the long-T group); after release into constant darkness, the short-T and long-T groups exhibited short and long taus, respectively. These animals were then induced to run in a novel exercise wheel for 3 h, starting at circadian time (CT) 7, or were exposed to 20 min of light, starting at CT 19. The size of the ensuing phase advances did not differ between the short-T and long-T groups not only for the nonphotic stimulus but also for the photic one, an unexpected result for the photic stimulus. Within the short-T groups for photic and nonphotic stimuli, the shorter tau was, the larger the phase advances were, another unexpected relationship. Another experiment where phase delays were induced by light pulses at CT 15 also failed to yield significant differences between the short-T and long-T groups. Independently of their after-effects on tau, T cycles may influence the capacity of the pacemaker to phase shift in ways that are still unclear but at least similar for both photic and nonphotic shifts. 相似文献
10.