全文获取类型
收费全文 | 1745篇 |
免费 | 47篇 |
国内免费 | 4篇 |
学科分类
工业技术 | 1796篇 |
出版年
2023年 | 13篇 |
2022年 | 23篇 |
2021年 | 45篇 |
2020年 | 26篇 |
2019年 | 29篇 |
2018年 | 23篇 |
2017年 | 40篇 |
2016年 | 46篇 |
2015年 | 29篇 |
2014年 | 45篇 |
2013年 | 77篇 |
2012年 | 75篇 |
2011年 | 67篇 |
2010年 | 58篇 |
2009年 | 75篇 |
2008年 | 63篇 |
2007年 | 83篇 |
2006年 | 61篇 |
2005年 | 62篇 |
2004年 | 56篇 |
2003年 | 42篇 |
2002年 | 45篇 |
2001年 | 32篇 |
2000年 | 40篇 |
1999年 | 34篇 |
1998年 | 126篇 |
1997年 | 79篇 |
1996年 | 64篇 |
1995年 | 44篇 |
1994年 | 34篇 |
1993年 | 29篇 |
1992年 | 20篇 |
1991年 | 14篇 |
1990年 | 16篇 |
1989年 | 9篇 |
1988年 | 12篇 |
1987年 | 14篇 |
1986年 | 10篇 |
1985年 | 18篇 |
1984年 | 4篇 |
1983年 | 10篇 |
1982年 | 10篇 |
1981年 | 15篇 |
1980年 | 8篇 |
1979年 | 11篇 |
1978年 | 4篇 |
1977年 | 17篇 |
1976年 | 16篇 |
1975年 | 6篇 |
1974年 | 4篇 |
排序方式: 共有1796条查询结果,搜索用时 15 毫秒
11.
K Andersson E Stadberg LA Mattsson G Rybo G Samsioe 《Canadian Metallurgical Quarterly》1996,41(5):476-483
Electrical stimulation of the basal temporal region of the dominant hemisphere before partial temporal lobectomy for epilepsy sometimes produces temporary interruption of language function, but the significance of removal of this area is unknown. We evaluated the correlation between resection of the basal temporal language areas (BTLA) and certain types of postoperative language deficits. In a population of 25 patients, we mapped the inferolateral temporal lobe with cortical electrical stimulation, verifying the positions of the stimulating electrodes with three-dimensional computed tomography (CT). Eighty percent of the patients developed transient language deficits with stimulation, particularly with tests of confrontation naming and comprehension. BTLA was primarily located in the fusiform gyrus, from 1 to 9 cm from the temporal tip. At testing 6-12 months after operation, patients with BTLA resection performed worse (mean 9% decrease) than those with no BTLA resection (mean 4% improvement) on tests of confrontation naming (p = 0.03). Resection size accounted for less of the variance in decrease in confrontation naming than did resection of the BTLA. Tests of performance I.Q. (PIQ), verbal I.Q. (VIQ), or recognition memory for word and verbal learning showed no significant difference between these groups. Most patients do not have language decrease with removal of basal temporal lobe 5-6 cm from the tip, even with removal of BTLA. Some patients, however, have persistent decrease in naming. 相似文献
12.
The transmission properties of perforated perfectly conducting screens are of practical interest. The treatment of nonperiodical structures by numerical techniques, such as the method of moments, is very computer intensive. In this paper it is shown that using basis functions that incorporate the edge as well as the corner singularities, the number of unknowns can be drastically reduced. The advantages and limitations of the method are discussed. Numerical results are presented illustrating the transmission properties of arrays of square and rectangular apertures 相似文献
13.
14.
Partial differential equations, describing the consumption of reactants and the formation of products, have been solved numerically for a step change from inert to reactant feed considering different variants of propene oxidation mechanisms. The response features and their dependency on the rate limiting step have been rationalised in terms of conclusions, which can serve as general guidelines for mechanistic interpretation of experimental transients from hydrocarbon oxidation over metal oxides. Though the response pattern is characteristic of the rate limiting step, it is demonstrated that different variants of mechanisms can give identical response features. In that case complementary investigation with other techniques, or more detailed mathematical analysis is necessary. 相似文献
15.
16.
17.
Possibilities and problems with the use of models as a communication tool in water resource management 总被引:2,自引:1,他引:1
Politicians and policy-makers, as well as modellers, often nurses an expectation that model derived results is an objective
source of information that can be used to support decisions. However, several prerequisites have to be dealt with in order
to ensure that models can be used as legitimate and efficient tools in water resource management. Based on empirical material
from recent studies on the use of models in stakeholder dialogues, mainly focusing on catchment nutrient transport, two central
problems are identified: (a) Models are laden with choices and thus depend on assumptions and priorities of modellers. (b)
There are several factors that influence ability and willingness of stakeholders (as information recovers) to criticize or
accept results of the modelling exercise. Recognized factors likely to influence stakeholders' acceptance of model derived
results include issues at stake, stakeholders' ability to criticize model derived information, and their trust in the institutions
that have developed or applied the used models. Identified prerequisites for successful use of models in integrated water
resource management include: consideration of user relevance, awareness of and preparedness to handle constraints linked to
communication of model-based results, transparency of used models and data and of involved uncertainties, mutual respect between
experts and stakeholders and between involved stakeholder groups, a robust institutional network, and sufficient time for
dialogues. Development and use of strategies for participatory modelling, based on a continuous dialogue between experts and
stakeholders is recommended as a way to facilitate that the prerequisites for a successful use of models in water resource
management are fulfilled. 相似文献
18.
The stability of cisplatin and its monohydrated complex has been studied in blood, plasma and plasma ultrafiltrate at 37 degrees C (pH 7.4). Intact cisplatin and the monohydrated complex were determined by liquid chromatography with post-column derivatization. The half lives for cisplatin and the monohydrated complex were 1.43 +/- 0.03 h (SEM) and 0.36 +/- 0.03 h (SEM), respectively, in blood and 0.88 +/- 0.05 h (SEM) and 0.26 +/- 0.02 h (SEM), respectively, in plasma. The compounds were unstable at -25 degrees C (t1/2 for cisplatin was 52 +/- 5 h (SEM) and for the monohydrated compound 26 +/- 2 h (SEM)), but at -70 degrees C both compounds were stable for at least 3 weeks. The monohydrated complex was found to be formed to a small extent when cisplatin was added to plasma (37 degrees C, pH 7.4). A sampling procedure using centripetal ultrafiltration of whole blood was evaluated and found applicable if the samples were stored at 0 degree C and ultracentrifuged within 1 h. 相似文献
19.
F Hammarqvist B Westman CE Leijonmarck K Andersson J Wernerman 《Canadian Metallurgical Quarterly》1996,119(4):417-423
A number of studies have localized CGRP to nerves in the cornea and iris, and it is thought that CGRP, along with other neuropeptides, is involved in pain sensation. It is also possible that CGRP could mediate trophic influences between nerve endings and corneal epithelium. This investigation utilized an in vitro rabbit corneal whole mount preparation to study the effect of topical 2.5 microM CGRP application on epithelial wound healing rates of 5 mm diameter epithelial wounds. CGRP (2.5 microM) was applied topically to 5 mm epithelial wounds at 0, 4, 16, 20, 24, 28, 40, 44, 48, 52, 56, 64, 68, and 72 hours after wounding and healing was visualized with fluorescein. CGRP was found to increase the epithelial wound healing rate by 25%, from 51 +/- 3 microns/hr for the control corneas, to 64 +/- 2 microns/hr for CGRP-treated corneas (mean +/- standard error, n = 10). Histological examination of the corneas following healing showed that the epithelium of the CGRP-treated corneas healed in a similar manner as in the control corneas. These findings may have clinical utility for the understanding and treatment of corneal and other epithelial wounds. 相似文献
20.
Florian A. Schmid J. Koudy Williams Thomas M. Kessler Arnulf Stenzl Wilhelm K. Aicher Karl-Erik Andersson Daniel Eberli 《International journal of molecular sciences》2021,22(8)
Urinary incontinence (UI) is a major problem in health care and more than 400 million people worldwide suffer from involuntary loss of urine. With an increase in the aging population, UI is likely to become even more prominent over the next decades and the economic burden is substantial. Among the different subtypes of UI, stress urinary incontinence (SUI) is the most prevalent and focus of this review. The main underlying causes for SUI are pregnancy and childbirth, accidents with direct trauma to the pelvis or medical treatments that affect the pelvic floor, such as surgery or irradiation. Conservative approaches for the treatment of SUI are pelvic physiotherapy, behavioral and lifestyle changes, and the use of pessaries. Current surgical treatment options include slings, colposuspensions, bulking agents and artificial urinary sphincters. These treatments have limitations with effectiveness and bear the risk of long-term side effects. Furthermore, surgical options do not treat the underlying pathophysiological causes of SUI. Thus, there is an urgent need for alternative treatments, which are effective, minimally invasive and have only a limited risk for adverse effects. Regenerative medicine is an emerging field, focusing on the repair, replacement or regeneration of human tissues and organs using precursor cells and their components. This article critically reviews recent advances in the therapeutic strategies for the management of SUI and outlines future possibilities and challenges. 相似文献