全文获取类型
收费全文 | 264篇 |
免费 | 6篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 64篇 |
金属工艺 | 8篇 |
机械仪表 | 2篇 |
建筑科学 | 11篇 |
能源动力 | 1篇 |
轻工业 | 28篇 |
无线电 | 27篇 |
一般工业技术 | 33篇 |
冶金工业 | 62篇 |
原子能技术 | 1篇 |
自动化技术 | 29篇 |
出版年
2023年 | 2篇 |
2022年 | 8篇 |
2021年 | 9篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 8篇 |
2015年 | 7篇 |
2014年 | 6篇 |
2013年 | 15篇 |
2012年 | 3篇 |
2011年 | 4篇 |
2010年 | 5篇 |
2009年 | 8篇 |
2008年 | 13篇 |
2007年 | 5篇 |
2006年 | 7篇 |
2005年 | 10篇 |
2004年 | 7篇 |
2003年 | 9篇 |
2002年 | 7篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 7篇 |
1998年 | 13篇 |
1997年 | 13篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 8篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1977年 | 1篇 |
1976年 | 5篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有270条查询结果,搜索用时 15 毫秒
1.
H. Heckhausen and J. Kuhl's (1985) goal typology provided the conceptual foundation for this research, which examined the independent and integrated effects of achievement orientation and goal-setting approaches on trainees' self-regulatory activity. Using a complex computer-based simulation, the authors examined the effects of 3 training design factors--goal frame, goal content, and goal proximity--cutting across these 2 theoretical domains on the nature, focus, and quality of the self-regulatory activities of 524 trainees. Results revealed that all 3 factors had a significant influence on self-regulation, with goal content exhibiting the greatest influence. In line with expectations, congruent learning frame and content compared with congruent performance frame and content was beneficial for trainees' self-regulatory activity, incongruent combinations of goal frame and content were better than congruent performance frames and content, and effects for the incongruent combinations cutting across the domains were asymmetrical. Theoretical extensions for further disentangling these distinct domains and training design implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
2.
Polyurethane coatings are highly flammable, and because of their widespread applications on different substrates (wood, steel, and building materials), there is a need to increase their fire‐safety properties. Intumescent additives sharply suppress the flammability properties of polyurethane coatings. Two problems accompany intumescent additives: their high loading percentage and incompatibility with polyurethane coatings. In this research, we succeeded in increasing the compatibility by mixing intumescent additives with a butyl acrylate polymer and in lowering the flame‐retardant additive loading (up to 20%) by incorporating newly modified montmorillonite. The flammability properties of the new intumescent coatings were characterized with a cone calorimeter. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
3.
S Kozlowski M Corr M Shirai LF Boyd CD Pendleton JA Berzofsky DH Margulies 《Canadian Metallurgical Quarterly》1993,151(8):4033-4044
T cell stimulation by certain class I-restricted antigenic peptides, such as the HIV 1 gp160-derived peptide, P18, requires peptide processing by angiotensin-1 converting enzyme (ACE) in FCS. We observed that longer versions of P18 and the murine cytomegalovirus pp89-derived core peptide, pMCMV, which could stimulate T cell hybridomas in FCS, were not as sensitive to the ACE inhibitor captopril as P18. Using cell-free soluble murine class I MHC molecules and protease inhibitors, we found that there are pathways of differing efficiency that use enzymes other than ACE for the proteolytic processing of peptides in serum. The kinetics of the generation of T cell stimulatory activity among P18 variant peptides in serum differed with peptide length, and with the nature of amino and COOH-terminal extensions. Such processing occurs in human plasma as well as in FCS. The understanding of this processing, its kinetics, and its inhibitors can lead to better design of peptide-based therapies, including vaccines. 相似文献
4.
D Kozlowski 《Canadian Metallurgical Quarterly》1998,94(27):54-55
Psychiatric nurses in the residential sector of St George's Hospital in Morpeth, Northumberland, worked with a quality coordinator to devise a means of auditing the quality of care in their wards. Their major objective was to bring the process to the grass roots of nursing care and involve front-line staff in designing and carrying it out. 相似文献
5.
Moulthrop AA Muha MS Hadimioglu B Silva CP Kozlowski GC 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》1992,39(2):204-211
The operation of an acoustic microscope having a resolution of 15 mm has been demonstrated. It uses as a coupling medium superfluid (4 )He colder than 0.9 K and pressurized to greater than 20 bar. The microscope has been used to image objects that show little or no contrast on a scanning electron microscope. In addition, the acoustic microscope has been used to study the properties of sound propagation in the coupling fluid. At low acoustic intensities, the coupling fluid has very low acoustic attenuation at the microscope's operating frequency (15.3 GHz), but near the focal point the acoustic intensity can be high enough that the helium behaves with extreme nonlinearity. In fact, this medium is capable of entering new regimes of nonlinear interaction. Plots of the received signal versus input power display a nearly complete source depletion at certain input power levels and a reconversion to the source frequency at higher power levels. Arguments that the process underlying this nonlinear behavior is harmonic generation are presented. 相似文献
6.
Dawid Polak Marcin Talar Nina Wolska Dagmara W. Wojkowska Kamil Karolczak Karol Kramkowski Tomasz A. Bonda Cezary Watala Tomasz Przygodzki 《International journal of molecular sciences》2021,22(6)
Blood platelets’ adenosine receptors (AR) are considered to be a new target for the anti-platelet therapy. This idea is based on in vitro studies which show that signaling mediated by these receptors leads to a decreased platelet response to activating stimuli. In vivo evidence for the antithrombotic activity of AR agonists published to date were limited, however, to the usage of relatively high doses given in bolus. The present study was aimed at verifying if these substances used in lower doses in combination with inhibitors of P2Y12 could serve as components of dual anti-platelet therapy. We have found that a selective A2A agonist 2-hexynyl-5’-N-ethylcarboxamidoadenosine (HE-NECA) improved the anti-thrombotic properties of either cangrelor or prasugrel in the model of ferric chloride-induced experimental thrombosis in mice. Importantly, HE-NECA was effective not only when applied in bolus as other AR agonists in the up-to-date published studies, but also when given chronically. In vitro thrombus formation under flow conditions revealed that HE-NECA enhanced the ability of P2Y12 inhibitors to decrease fibrinogen content in thrombi, possibly resulting in their lower stability. Adenosine receptor agonists possess a certain hypotensive effect and an ability to increase the blood–brain barrier permeability. Therefore, the effects of anti-thrombotic doses of HE-NECA on blood pressure and the blood–brain barrier permeability in mice were tested. HE-NECA applied in bolus caused a significant hypotension in mice, but the effect was much lower when the substance was given in doses corresponding to that obtained by chronic administration. At the same time, no significant effect of HE-NECA was observed on the blood–brain barrier. We conclude that chronic administration of the A2A agonist can be considered a potential component of a dual antithrombotic therapy. However, due to the hypotensive effect of the substances, dosage and administration must be elaborated to minimize the side-effects. The total number of animals used in the experiments was 146. 相似文献
7.
Cezary Graczykowski Tomasz Lewiński 《Structural and Multidisciplinary Optimization》2010,42(6):869-877
The paper delivers the benchmark results for the Michell cantilevers constructed within a half strip, for selected values
of the σ
T
/σ
C
ratio, σ
T
, σ
C
being the admissible stresses in tension and compression, respectively. 相似文献
8.
9.
V. A. Baranov V. A. Kalinnikov V. V. Karpukhin N. V. Khomutov A. S. Korenchenko S. M. Korenchenko N. P. Kravchuk N. A. Kuchinskii D. A. Mzhaviya A. M. Rozhdestvenskii V. V. Sidorkin Z. B. Tsamalaidze T. Sakhelashvili E. Frlež D. Počanić W. Li R. C. Minehart L. C. Smith W. A. Stephens K. O. H. Ziock W. Bertl R. Horisberger S. Ritt R. Schnyder H. P. Wirtz B. G. Ritchie I. Supek T. Kozlowski 《Instruments and Experimental Techniques》2005,48(2):168-176
The construction and characteristics of the PIBETA spectrometer are described. This spectrometer is designed to implement a program of precise measurement of pion decay + 0 + e
+ + e at the Paul Scherrer Institute (Switzerland). A spherical calorimeter, consisting of 240 crystals of pure CsI scintillator and embracing a solid angle of 3, is the main detector of the setup. In addition, the spectrometer is composed of an active collimator (which also acts as a beam degrader), a segmented active plastic target, two multiwire cylindrical proportional chambers, a 20-element cylindrical plastic hodoscope, and veto counters of cosmic muons.__________Translated from Pribory i Tekhnika Eksperimenta, No. 2, 2005, pp. 39–48.Original Russian Text Copyright © 2005 by Baranov, Kalinnikov, Karpukhin, Khomutov, A. Korenchenko, S. Korenchenko, Kravchuk, Kuchinskii, Mzhaviya, Rozhdestvenskii, Sidorkin, Tsamalaidze, Sakhelashvili, Frlez, Poanic, Li, Minehart, Smith, Stephens, Ziock, Bertl, Horisberger, Ritt, Schnyder, Wirtz, Ritchie, Supek, Kozlowski. 相似文献
10.
Yuki Chikahiro Ichiro Ario Piotr Pawlowski Cezary Graczykowski Jan Holnicki‐Szulc 《Computer-Aided Civil and Infrastructure Engineering》2019,34(6):523-538
Scissors mechanisms are commonly used in safety engineering during the construction of temporary structures, owing to their inherent advantages of foldability, transformability, and reusability. We effectively utilized these scissors mechanism features to develop a lightweight, deployable emergency Mobile Bridge (MB) based on optimization, and control of the folding structure. Here, we discuss the problems of optimal reinforcement layout for the MB by formulating and solving three optimization problems, namely: (a) the load capacity maximization problem, (b) the weight minimization problem, and (c) coupling the load capacity maximization problem and the weight minimization problem. The potential benefits resulting from the application of reinforcement were evaluated using a combination of finite element analysis and an optimization algorithm based on the differential evolution method. The results demonstrate the significant positive influence of the additional reinforcing members. In particular, the limit load was increased by over 10 times, while the weight was decreased to approximately half. The proposed methodology enabled the development of a substantially improved version of the MB characterized by a higher load capacity and lower weight in comparison to the initial bridge design. 相似文献