全文获取类型
收费全文 | 1111篇 |
免费 | 14篇 |
专业分类
电工技术 | 14篇 |
综合类 | 2篇 |
化学工业 | 91篇 |
金属工艺 | 14篇 |
机械仪表 | 11篇 |
建筑科学 | 26篇 |
矿业工程 | 1篇 |
能源动力 | 14篇 |
轻工业 | 116篇 |
水利工程 | 5篇 |
石油天然气 | 3篇 |
无线电 | 86篇 |
一般工业技术 | 143篇 |
冶金工业 | 442篇 |
原子能技术 | 20篇 |
自动化技术 | 137篇 |
出版年
2021年 | 11篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2018年 | 7篇 |
2017年 | 6篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 18篇 |
2013年 | 47篇 |
2012年 | 30篇 |
2011年 | 39篇 |
2010年 | 32篇 |
2009年 | 29篇 |
2008年 | 26篇 |
2007年 | 46篇 |
2006年 | 34篇 |
2005年 | 22篇 |
2004年 | 27篇 |
2003年 | 34篇 |
2002年 | 27篇 |
2001年 | 20篇 |
2000年 | 25篇 |
1999年 | 25篇 |
1998年 | 110篇 |
1997年 | 73篇 |
1996年 | 59篇 |
1995年 | 37篇 |
1994年 | 31篇 |
1993年 | 36篇 |
1992年 | 13篇 |
1991年 | 12篇 |
1990年 | 11篇 |
1989年 | 13篇 |
1988年 | 17篇 |
1987年 | 12篇 |
1986年 | 14篇 |
1985年 | 9篇 |
1984年 | 9篇 |
1983年 | 6篇 |
1982年 | 12篇 |
1981年 | 17篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 14篇 |
1976年 | 23篇 |
1974年 | 7篇 |
1972年 | 6篇 |
1971年 | 6篇 |
1969年 | 5篇 |
排序方式: 共有1125条查询结果,搜索用时 317 毫秒
151.
JF Burke WC Quinby CC Bondoc EM Sheehy HC Moreno 《Canadian Metallurgical Quarterly》1977,186(3):377-387
A new system of patient protection from bacterial crossinfection called the Bacteria Controlled Nursing Unit (BCNU) is described, based on strict environmental control of a 6 x 10 foot area surrounding the patient's bed rather than the entire patient room or isolation ward, plus the ability to deliver all medical care without entering the protective environment and maintaining all monitoring, life support, and i.v. equipment outside the controlled environment. The clinical effectiveness of this system in the treatment of burn patients has been studied and compared with the effectiveness of single room isolation on a burn isolation ward and conventional isolation techniques on an open burn ward. The studies show that the BCNU is significantly more effective in preventing bacterial cross-contamination than conventional precautions (3.8% vs. 13.1%, P < 0.001; and 8% vs. 22.8%, P < 0.001) over a two and four week period. The studies also indicate that there was a significant increase in the probability of infection occurring following cross-contamination than occurring after auto-contamination (65% vs. 39%, P < 0.005), emphasizing the importance of preventing cross-contamination in reducing the overall infection rate in seriously burned patients. Clinical evaluation of the unit proved it to be compatible with intensive nursing and medical care without increasing the nurse to patient ratio. The unit provided sufficient control of bacterial cross-infection to allow reduction in mortality and improvement in the effectiveness of burn care through routine prompt excision of burn eschar and immediate wound closure to be carried out in severe and massively burned patients without a limiting threat of bacterial burn wound sepsis. 相似文献
152.
153.
Argues that organization development is increasingly recognized as an appropriate function for the school psychology specialty as a whole. It is suggested, however, that prior to introducing organization development in a particular school district, several considerations are appropriate. These prerequisite considerations include (a) resources needed for organization-development programs, (b) school readiness criteria for organization-development programs, (c) interventions available for schools lacking readiness, and (d) factors unique to the individual school psychologist. Particular attention is given to a continuum of school practice ranging from provision of specific organization-development interventions through sustained organization-development programs. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
154.
The formation of hydrous oxide films on gold in base under potential cycling conditions was investigated and found to be less inhibited than the same type of reaction observed when gold is strongly anodized at high potentials under d.c. conditions at high pH. The overall behaviour on cycling is quite similar to that observed with other metals, e.g. platinum. The importance of the lower limit, for instance, again appears to be related to the need under film thickening conditions to significantly reduce the compact oxide layer formed on the metal surface during the anodic sweep. It was noted that the earlier duplex model for this type of system, i.e. an inner compact and an outer dispersed oxide layer, is not always valid. Under certain conditions about six distinct peaks (suggesting six different states of gold oxide hydration, dispersion or polymerization) were observed in cathodic sweeps recorded for the reduction of thick films grown on gold under potential cycling conditions in base. 相似文献
155.
J. R. Blanchfield 《Food Control》1993,4(4):178-180
An IFST-led Joint Working Group has developed a scheme to allow a visually impaired person to access the information on food labels, when shopping and in the home. The device would consist of a portable data storage and playback device, such as a CD-ROM player with product information stored on a compact disc, referenced by scanning a product bar code with a hand-held modified bar code scanner and delivered to the user by synthesized speech. 相似文献
156.
Fura-2 and its lipid analogue, FFP-18, were used to measure changes in cytosolic free Ca2+ concentration within human neutrophils. Whereas fura-2 was employed to monitor cytosolic Ca2+ increases throughout the cytosol, FFP-18 was used to monitor Ca2+ changes only near the membrane. This latter probe was incorporated into the plasma membrane as its acetoxymethyl ester (FFP-18-AM) but as de-esterification was catalysed by cytosolic esterases, the Ca(2+)-sensing probe (FFP-18 acid) accumulated on the inner face of membrane. The fluorescence of esterified probe on the extracellularly facing membrane leaflet was quenched by the membrane-impermeant ion Ni2+. Under these conditions, near membrane Ca2+ changes which resulted from the release of Ca2+ from intracellular stores was possible by conventional ratio fluorescence measurement of FFP-18. From the timing of arrival of Ca2+ at the plasma membrane, it was proposed that there were two Ca2+ storage sites, liberated by different stimuli, one close to the plasma membrane and the other more distant. In order to discover whether organelles within the neutrophil had distributions which correlate with the Ca2+ release sites, fluorescent dyes for structures within the cytosol were employed. We have previously shown that the location of the intracellular membrane stain, DiOC6 (3) corresponds to the distant Ca2+ release site. Here a second stain, BODIPY-C5 ceramide, has also been used and is shown to stain a peripheral region of the neutrophil, in a similar pattern to the near membrane Ca2+ storage site. These data therefore raise the question of whether these stains mark the organelles in neutrophils which are the two Ca2+ storage and release sites. 相似文献
157.
O Elkayam D Levartovsky C Brautbar M Yaron M Burke N Vardinon D Caspi 《Canadian Metallurgical Quarterly》1998,105(6):484-487
PURPOSE: Prolonged treatment with minocycline for acne vulgaris has been associated with the development of arthralgia, arthritis, and other autoimmune phenomena. We characterized the clinical, laboratory, and immunological profiles of seven patients with this syndrome. SUBJECTS AND METHODS: Clinically the patients were studied with special emphasis on prior minocycline treatment, presenting symptoms, physical findings, course, and outcome. Laboratory tests included fluorescent antinuclear and antineutrophil cytoplasmic (ANCA) antibodies, as well as antibodies to myeloperoxidase, bactericidal permeability increasing protein, elastase, cathepsin G, lactoferrin, cardiolipin, and histone. RESULTS: All 7 patients presented with polyarthritis or arthralgia, morning stiffness, and fever after 6 to 36 months of minocycline treatment. The skin was involved in five patients (three with livedo reticularis and two with subcutaneous nodules). Two patients had chronic active hepatitis. Increased titers of perinuclear ANCA (p-ANCA) were detected in all seven patients; five patients had fluorescent antinuclear antibodies, two had antihistone autoantibodies and one had anticardiolipin antibodies. Antigenic characterization of p-ANCA disclosed antibodies to bactericidal permeability increasing protein in one patient, to elastase in three patients, and to cathepsin G in five patients. Symptoms resolved in five patients upon discontinuation of minocycline; the other two patients were treated with corticosteroids and also achieved remissions. CONCLUSION: Minocycline-induced autoimmune syndrome is characterized by reversible polyarthralgia or arthritis, morning stiffness, fever, frequent skin involvement, occasional chronic active hepatitis, and increased titers of p-ANCA with various minor p-ANCA-related antigens. 相似文献
158.
159.
The biological heterogeneity of AML makes growth factor augmentation of cell cycle-dependent chemotherapy unlikely to be successful for all patients. Patients whose leukemic cells empirically demonstrate cytokine-induced chemosensitization in vitro might benefit from the concurrent administration of growth factors during consolidation chemotherapy. We have explored the growth factor-dependence and response of primary bone marrow samples from patients with AML at diagnosis, remission, and relapse to determine whether minimal residual leukemia remains growth factor-responsive. Most cases of AML studied at all phases of treatment were growth factor-responsive. Growth factor response of occult remission clonogenic leukemic precursors (CFU-L) was usually concordant with their response at diagnosis. Occult CFU-L were markedly resistant to cytosine arabinoside (median LD99% 20 microM); preincubation with IL-3 or GM-CSF did not significantly improve their ara-C sensitivity. While occult remission CFU-L appear to remain growth factor-responsive, it appears unlikely that growth factor augmentation of consolidation chemotherapy will overcome the important problem of drug resistance of residual leukemia. 相似文献
160.
Examined semantic processing of sentences by 30 younger (mean age 25.1 yrs) and 30 older (mean age 68.5 yrs) adults, using a priming technique. Ss read a sentence and then made a lexical decision about a target presented immediately after the sentence. For both age groups, word targets that were instruments implied by the action of the sentence had faster latencies than unrelated word targets. There was no evidence of inhibition of unrelated targets, suggesting that the facilitation of instrument targets involved automatic processes. Results provide no evidence for age-related changes in semantic processing of sentences, including access to implied information. Older Ss did, however, have poorer memory for the sentences on a recognition test. It is suggested that previous findings by G. Cohen (see PA, Vols 63:747 and 67:958) of age deficits in comprehension may depend on techniques that measure what is remembered rather than what is understood. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献