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41.
NJ Hoeldtke PG Napolitano KH Moore BC Calhoun RF Hume 《Canadian Metallurgical Quarterly》1997,177(5):1088-1092
OBJECTIVES: Our purpose was to determine the effects of acidosis and acidosis-hypoxia on fetoplacental perfusion pressure and its response to angiotensin II. STUDY DESIGN: Perfused cotyledons from 14 placentas were studied with either an acidotic fetal circuit perfusate (n = 7) or an acidotic-hypoxic fetal circuit perfusate (n = 7). Each cotyledon's fetal vasculature was initially perfused under standard conditions and bolus injected with 1 x 10(-10) moles of angiotensin II. Fetoplacental perfusate was then replaced with either an acidotic medium (pH 6.90 to 7.00 and Po2 516 to 613 mm Hg) or an acidotic-hypoxic medium (pH 6.90 to 7.00 and Po2 20 to 25 mm Hg) followed by an angiotensin II injection. The vasculature was subsequently recovered with standard perfusate and again injected with angiotensin II. Perfusion pressures within each group were compared by one-way analysis of variance, and results were expressed as mean pressure +/- SEM. RESULTS: Resting fetoplacental perfusion pressure did not change when the fetal circuit perfusate was made acidotic (28 +/- 1 mm Hg vs 25 +/- 2 mm Hg) or acidotic-hypoxic (26 +/- 2 mm Hg vs 25 +/- 2 mm Hg). The maximal fetoplacental perfusion pressure achieved in response to angiotensin II did not differ with an acidotic perfusate (41 +/- 2 mm Hg vs 38 +/- 1 mm Hg) or with an acidotic-hypoxic perfusate (39 +/- 2 mm Hg vs 36 +/- 2 mm Hg). CONCLUSIONS: In the perfused placental cotyledon fetoplacental perfusion pressure and pressor response to angiotensin II are not affected by fetal circuit acidosis or acidosis-hypoxia. This suggests that neither fetal acidosis nor fetal acidosis combined with hypoxia has a direct effect on fetoplacental vascular tone. 相似文献
42.
This article discusses decisions involving whether to terminate late-term pregnancies when fetal anomalies have been detected. Partial-birth abortion performed on fetuses with chromosomal abnormalities, while performed under the guise of reducing suffering, threatens the best interests of the mother and infant. An alternative for parents faced with the decision to terminate their pregnancy is perinatal hospice. Perinatal hospice recognizes the value of bringing these infants to term by treating them as beings conceived with a tangible future. This alternative is preferred because of post-termination psychological distress and because biblical teachings emphasize the dignity and worth of each fetus. Perinatal hospice supports parents through their grief when their infant dies and maximizes the opportunity for authentic mourning. 相似文献
43.
Golnoosh Farnadi Geetha Sitaraman Shanu Sushmita Fabio Celli Michal Kosinski David Stillwell Sergio Davalos Marie-Francine Moens Martine De Cock 《User Modeling and User-Adapted Interaction》2016,26(2-3):109-142
A variety of approaches have been recently proposed to automatically infer users’ personality from their user generated content in social media. Approaches differ in terms of the machine learning algorithms and the feature sets used, type of utilized footprint, and the social media environment used to collect the data. In this paper, we perform a comparative analysis of state-of-the-art computational personality recognition methods on a varied set of social media ground truth data from Facebook, Twitter and YouTube. We answer three questions: (1) Should personality prediction be treated as a multi-label prediction task (i.e., all personality traits of a given user are predicted at once), or should each trait be identified separately? (2) Which predictive features work well across different on-line environments? and (3) What is the decay in accuracy when porting models trained in one social media environment to another? 相似文献
44.
Kevin M. Holloway Greg M. Reger 《International journal of human-computer interaction》2013,29(9):594-603
Deploying Active Duty Service Members face multiple psychological health risks, including posttraumatic stress disorder (PTSD). Despite a significant proportion of Service Members with psychological health needs, a number of barriers prevent access to education and treatment services available to them. These barriers include perceived stigma, physical access barriers, and psychological barriers. Web resources provide important information regarding psychological health issues and available resources but have limitations in the learning experience they can provide. Virtual worlds platforms, such as Second Life, offer unique affordances that may reduce some barriers to accessing psychological health education and care. They may allow for a unique immersive and interactive learning experience augmenting current web resources. One such virtual world environment, the T2 Virtual PTSD Experience, is described. The T2 Virtual PTSD Experience aims to educate military service members, veterans, family, and peers about the causes, symptoms, and help available for combat-related PTSD. Reactions from visitors have been positive, with many reporting improved understanding of PTSD and motivation to seek care. Future directions for leveraging virtual worlds in the service of psychological health care are discussed. 相似文献
45.
Codesigning tends to be identified with collaborative endeavours to produce designs. In this study, grounded in an anthropology of making, we propose a radically different use of the ‘co-’ that emphasises the continued becoming and mutual shaping of people-and-materials-becoming-design. An extended case study of a design critique presentation from a graduate course in industrial design is used to exemplify this different perspective. It expands upon the common use of the understanding of codesigning by bringing to the fore not only the back-and-forth movement of people and evolving designs in correspondence with each other but also the transverse movement, which is the intertwining streams of perduring life. Codesign is thus understood as a process of designer, materials and designed objects coming into correspondence while corresponding (conversing) with each other, and all designing is understood as codesigning The approach decentres common agent-centred notions of designing to focus on the continued becoming-design that shapes designers and their materials alike. 相似文献
46.
M.A. Stanish 《Drying Technology》2013,31(8):1879-1895
ABSTRACT The crook instability of lumber at moisture contents below the fiber saturation point was studied using both experiments and mathematical modeling. The changes in overall length and in crook that were observed with environmental humidity cycling at ambient temperature suggest that crook instability at such conditions is determined largely by elastic phenomena. Consequently, a simplified mathematical model of crook instability based on only elastie paramelers was created and verified using property data and crook measurements from selected boards. Results indicate that the elastic model accurately describes crook instability in the hygroscopic moisture content range near ambient temperatures. Experimental observations also show that board-to-board differences in crook instability can be quite complex. A better fundamental understanding of wood shrinkage behavior would help to explain these differences. 相似文献
47.
《Construction and Building Materials》2010,24(8):1385-1391
The behaviour of masonry under seismic loads has recently become of great interest. New methods for design and analysis, as well as for resistance, have been developed. The main focus has been on experimental and analytical research for the development of new brick material and mortar. With the introduction of Eurocode 8, the behaviour of old masonry structures under seismic load became an interesting topic for engineers. In particular, the available resistance capacity of existing masonry structures is highly relevant to the restructuring of existing buildings. Laboratory tests on masonry walls were performed in order to determine the mechanical behavioural characteristics of old brick material. 相似文献
48.
《International Journal of Hydrogen Energy》2022,47(10):6569-6585
An optimum design and energy management of various distributed energy resources is investigated in a hybrid microgrid system with the examination of electrical, heating, and cooling demand. This paper suggested an optimal approach to design and operate a microgrid incorporating with battery energy storage, thermal energy storage, photovoltaic arrays, fuel cell, and boiler with minimization of the total operational cost of the hybrid microgrid. Two different hydrogen production methods are considered to assure the advantage of the developed proposed methodology. Furthermore, besides natural gas, residential and municipal wastes are collected and are utilized to produce electricity in fuel cell units. Load growth for different type of loads is also considered. The new number of households are added to the proposed system in different years and the proposed program is determined the optimum size of each employed resources to add each year for satisfying the total demand. To find out the optimum energy management and the optimum capacity of each employed distributed energy resources, a meta-heuristic Particle Swarm Optimization Algorithm is utilized. It is concluded from the results that by utilizing residential waste, the amount of natural gas consumption by fuel cells is reduced about 6.2%, and by utilizing residential plus municipal waste, the reduction is about 26.7%. It is also observed that the amount of CO2 emission is reduced significantly (46.8%) in the case of utilization of produced heat by fuel cells. Finally, the results confirmed the efficacy of the suggested optimal energy management of the hybrid microgrid. 相似文献
49.
This study numerically simulates strain-rate dependent transverse tensile failure of unidirectional composites. The authors’ previous study reported that the failure mode depends on the strain rate, with an interface-failure-dominant mode at a relatively high strain rate and a matrix-failure-dominant mode at relatively low strain rate. The present study aims to demonstrate this failure-mode transition by a periodic unit-cell simulation containing 20 fibers located randomly in the matrix. An elasto-viscoplastic constitutive equation that involves continuum damage mechanics regarding yielding and cavitation-induced brittle failure is used for the matrix. A cohesive zone model is employed for the fiber–matrix interface, considering mixed-mode interfacial failure. For the results, the relationship between failure modes and the strain rate is consistent with the authors’ previous studies. 相似文献
50.
Siddharth Ramakrishnan 《AI & Society》2013,28(4):549-552
In 1952, Alan Turing published his last work on the concept of embryonic morphogenesis, propounding a computational framework for pattern formation within the developing embryo. This concept of morphogenesis and the concept of embryo pattern formation based on chemical diffusion patterns were corroborated with the discovery of the Homeobox or Hox genes. In the following decades, Hox gene research has expanded and is now shown to underlie the variety of morphological novelties that we experience in nature, the patterning of structural aspects of different organs including the brain and also mutant animals that may in the future give rise to novel speciation. Turing had the foresight and vision and with his work created the field of computational biology and mathematical modeling in biological systems. In this paper, we will discuss the concept of Hox genes, their role in patterning the embryo, how it relates to Turing’s concept of morphogenesis and what further insights they may provide. 相似文献