全文获取类型
收费全文 | 1097篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 6篇 |
金属工艺 | 2篇 |
机械仪表 | 2篇 |
建筑科学 | 3篇 |
能源动力 | 1篇 |
轻工业 | 4篇 |
无线电 | 10篇 |
一般工业技术 | 3篇 |
冶金工业 | 1046篇 |
自动化技术 | 22篇 |
出版年
2021年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2013年 | 5篇 |
2012年 | 1篇 |
2010年 | 3篇 |
2009年 | 1篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 1篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2000年 | 1篇 |
1999年 | 36篇 |
1998年 | 330篇 |
1997年 | 162篇 |
1996年 | 124篇 |
1995年 | 56篇 |
1994年 | 69篇 |
1993年 | 69篇 |
1992年 | 6篇 |
1991年 | 13篇 |
1990年 | 13篇 |
1989年 | 10篇 |
1988年 | 12篇 |
1987年 | 9篇 |
1986年 | 8篇 |
1985年 | 9篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 9篇 |
1980年 | 13篇 |
1979年 | 3篇 |
1977年 | 33篇 |
1976年 | 64篇 |
1975年 | 3篇 |
1968年 | 1篇 |
1954年 | 2篇 |
排序方式: 共有1100条查询结果,搜索用时 0 毫秒
1.
2.
The mirror effect for word frequency refers to the finding that low-frequency words have higher hit rates and lower false alarm rates than high-frequency words. This result is typically interpreted in terms of conventional signal detection theory (SDT), in which case it indicates that the order of the underlying old item distributions mirrors the order of the new item distributions. However, when viewed in terms of a mixture version of SDT, the order of hits and false alarms does not necessarily imply the same order in the underlying distributions because of possible effects of mixing. A reversal in underlying distributions did not appear for fits of mixture SDT models to data from 4 experiments. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
3.
D Brodaty G Dreyfus C Dubois P De Lentdecker C Barbagelatta PF Bouchet LJ Couderc O Bletry P Honderlick D Guilmet 《Canadian Metallurgical Quarterly》1998,91(12):1525-1529
The authors report a case of giant cell myocarditis leading to rapidly progressive cardiac failure despite immuno-suppressor treatment in a 20 year old woman. The cardiac failure was successfully managed by implantation of a left ventricular assist device and then cardiac transplantation. The problems encountered underline the importance of accurate diagnosis by endomyocardial biopsy before undertaking treatment and the difficulties in the choice of appropriate method of assistance in this indication. Giant cell myocarditis is a rare cause of cardiac failure and should be considered in the differential diagnosis in view of its clinical features and risk of progression. The literature and the therapeutic implications are discussed. 相似文献
4.
5.
PF Beales 《Canadian Metallurgical Quarterly》1997,91(7):713-718
Mortality from malarial anaemia and malarial infection in those who are already anaemic yet have some degree of compensation is now beginning to receive the attention it deserves. It is of particular concern in Africa and especially in young children and pregnant women. The asymptomatic parasitaemia remaining after poor response to full antimalarial treatment may lead to life-threatening anaemia; as drug-resistant strains of the malarial parasite proliferate this is becoming increasingly important. It is now possible to estimate haemoglobin levels, simply, cheaply, easily and safely, using a haemoglobin colour scale which is being developed by the World Health Organization. The potential and practical value of this scale in malaria-control programmes was demonstrated in a small, preliminary trial in 1995. Estimation of anaemia should become an additional parameter in the traditional malariometric survey. Haemoglobin concentrations should also be taken into consideration in the management of malaria patients at the primary-care level, particularly in deciding whether a patient should be referred to an appropriate treatment centre. The accurate prediction of clinical outcome of malaria and anaemia, and indication of the appropriate action (determined by a case-based reasoning device) should be possible in the near future. 相似文献
6.
7.
PF Tosi D Schwartz U Sharma Y Mouneimne J Hannig G Li G McKinley M Grieco CW Flexner J Lazarte D Norse C Nicolau DJ Volsky 《Canadian Metallurgical Quarterly》1996,87(11):4839-4844
Human erythrocytes bearing electroinserted full-length CD4 (RBC-CD4) can bind and fuse with a laboratory strain of human immunodeficiency virus type 1 (HIV-1) or with T cells infected by HIV-1. Here we show that RBC-CD4 neutralize primary HIV-1 strains in an assay of cocultivation of peripheral blood mononuclear cells (PBMC) from HIV-1-infected persons with uninfected PBMC. RBC-CD4 inhibited viral p24 core antigen accumulation in these cocultures up to 10,000-fold compared with RBC alone. Viral p24 accumulation was inhibited equally well when measured in culture supernatants or in call extracts. The inhibition was dose-dependent and long-lived. Two types of recombinant CD4 tested in parallel were largely ineffective. The neutralization of primary HIV-1 by RBC-CD4 in vitro was demonstrated in PBMC cultures from 21 of a total of 23 patients tested at two independent sites. RBC-CD4 may offer a route to blocking HIV-1 infection in vivo. 相似文献
8.
The present paper deals with the toxic effects of aluminum lactate (Al(lact)3) in rabbits. Experimental animals were injected with 6.2 mg of Al(III) as Al(lact)3 aqueous solutions at neutral pH for 21 days. Histological examination showed different pathological lesions to the myocardial tissue, spleen, kidney and liver, with no relevant effects to lungs and CNS. On the contrary, rabbits injected with 60 micrograms of Al(III) as Al(lact)3 in a liposome suspension for 42 days showed a large infarctual zone in the spinal cord with the metal accumulation in the necrobiotic neurons. Pharmacological implications of these findings are also discussed. 相似文献
9.
A Iezzi N Magarelli A Carriero PF Podda C Ciccotosto L Bonomo 《Canadian Metallurgical Quarterly》1994,88(1-2):24-30
In an experiment designed to distinguish between the behavioral consequences of treatment with SCH-23390, a D1 dopamine receptor blocker, and raclopride, a D2 antagonist, rats were trained to perform a water-reinforced forelimb operant response. Response rate and the duration of each forelimb contact with the operandum were recorded. In addition, the durations of the rat's visits to the reward well were detected by a photobeam which was blocked by the rat's muzzle as it remained at the reward well. In a between-groups dosing design, separate groups of rats (11-13 rats/group) received SCH-23390 (0, 0.01, 0.02, 0.04, 0.08, 0.12 mg/kg, IP, 30 min) or raclopride (0. 0.05, 0.1, 0.2, 0.4, 0.8 mg/kg, IP, 30 min) for 21 consecutive days. Quantitative analyses indicated that for comparable amounts of operant rate reduction, raclopride had a significantly greater tendency than SCH-23390 to increase the duration of operant responses and to increase the maximum muzzle entry duration (i.e., to induce microcatalepsy). The results support the idea that at relatively low doses D2 antagonism is more likely than D1 antagonism to produce effects identified preclinically with extrapyramidal side effects. 相似文献
10.
Stress fracture of the sternum is a rare condition which presents as acute anterior chest pain after repetitive upper-body exercise. Two case reports are presented and it is postulated that this is an often underdiagnosed condition which should be considered in the differential diagnosis of acute chest pain in the athlete. Awareness of the injury together with meticulous clinical examination supported by good quality radiographs or isotope bone scan may lead to an increase in the diagnosis of this injury. 相似文献