全文获取类型
收费全文 | 120篇 |
免费 | 5篇 |
专业分类
化学工业 | 19篇 |
机械仪表 | 1篇 |
建筑科学 | 4篇 |
能源动力 | 1篇 |
轻工业 | 8篇 |
水利工程 | 6篇 |
无线电 | 6篇 |
一般工业技术 | 9篇 |
冶金工业 | 44篇 |
自动化技术 | 27篇 |
出版年
2023年 | 2篇 |
2022年 | 6篇 |
2021年 | 4篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 7篇 |
2012年 | 4篇 |
2011年 | 4篇 |
2010年 | 6篇 |
2009年 | 5篇 |
2008年 | 6篇 |
2007年 | 1篇 |
2006年 | 5篇 |
2005年 | 6篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
排序方式: 共有125条查询结果,搜索用时 15 毫秒
91.
Forsythe Chris; Milliken Garrett W.; Stafford Donna K.; Ward Jeannette P. 《Canadian Metallurgical Quarterly》1988,102(3):248
The hand preferences of 5 semi-free-ranging black-and-white ruffed lemurs were assessed by using three distinct testing procedures. Testing conditions varied in the extent to which they required animals to make a whole body postural adjustment prior to making a reach. Minimal bodily adjustment was necessary for free foraging, whereas discrete food presentations on land (DFP-land) and in a moat (DFP-moat) promoted a gross reorientation of the animal's entire body. In the DFP-moat condition 4 animals exhibited exclusive use of the left hand, and only 1 of 515 reaches was made with the right hand. Similarly, all 5 animals showed a pronounced left-hand preference in the DFP-land condition. The free-foraging condition revealed a hand preference for only 1 of the 5 subjects, and that preference was weak in comparison with those measured in the other two test conditions. These findings indicate that whole body postural adjustments critically influenced the expression of hand preference and should be taken into consideration in future studies of primate hand preferences. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
92.
These notes are personal reflections, stemming from attempts to understand the sources of problems and successes in the application of work on formal specifications. Our intent is to provoke thought about the nature and value of work in the area; not to provide a set of well-tested results. Rather than focusing on yet another specification language, we have tried to take a broad view of the role of formal specifications in the program development process. 相似文献
93.
Clara Piccirillo Alessio Adamiano David M. Tobaldi Marco Montalti Jeannette Manzi Paula M. Lima Castro Silvia Panseri Monica Montesi Simone Sprio Anna Tampieri Michele Iafisco 《Journal of the American Ceramic Society》2017,100(8):3402-3414
The recovery of valuable compounds from byproducts is at present a priority topic for social, environmental, and economic reasons. In this work we report for the first time the preparation of luminescent calcium phosphate (CaP) bioceramics from waste codfish bones. Codfish bones were treated in aqueous Eu(NO3)3 solutions of different concentrations, followed by thermal treatment at either 700°C or 1100°C. The resulting materials consisted of hydroxyapatite (HAp), β‐tricalcium phosphate (β‐TCP) and a small amount of Eu2O3. Chemical and structural characterization showed that the Eu ions were successfully introduced into the bones and, hence, in the thermally treated CaP phases obtained from them, although mainly in the β‐TCP lattice. Photoluminescence investigation revealed that all the materials are luminescent, with samples treated at 1100°C having more intense luminescence than those prepared at 700°C. In vitro evaluation of cell‐materials interaction indicated that all the samples displayed good cytocompatibility toward osteoblast cells. This work demonstrates that a simple and effective process, employing Eu as a dopant, can convert fish industry byproducts into highly valuable luminescent CaP bioceramics, having potential applications in biology and medicine for bio‐imaging. 相似文献
94.
Xu-Liang Cao Jeannette Corriveau 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2013,30(4):482-486
A method based on isotope dilution headspace and gas chromatography–mass spectrometry was developed for the determination of propylene oxide in foods. Optimum method sensitivity was achieved by the addition of NaCl in water at saturation and with the sample solution incubated at 90°C. The method had good repeatability with relative standard deviations of 6.0, 7.6 and 2.2% at 5, 20 and 40 µg l?1, respectively. The method was used to determine propylene oxide in 36 selected food composite samples from the 2007 Canadian total diet study. Propylene oxide was not detected in any samples analyzed with an average method detection limit of 0.5 ng g?1. Hydrolysis of propylene oxide in water was observed as a first-order reaction with a half-life of 15 h at room temperature and less than 10 min at 90°C. This confirms that it is very unlikely to find propylene oxide in foods as consumed due to its volatility and reaction with water. 相似文献
95.
Adler Nancy E.; Epel Elissa S.; Castellazzo Grace; Ickovics Jeannette R. 《Canadian Metallurgical Quarterly》2000,19(6):586
This preliminary study compared the associations between objective and subjective socioeconomic status (SES) with psychological and physical variables among 157 healthy White women, 59 of whom subsequently participated in a laboratory stress study. Compared with objective indicators, subjective social status was more consistently and strongly related to psychological functioning and health-related factors (self-rated health, heart rate, sleep latency, body fat distribution, and cortisol habituation to repeated stress). Most associations remained significant even after controlling for objective social status and negative affectivity. Results suggest that, in this sample with a moderately restricted range on SES and health, psychological perceptions of social status may be contributing to the SES-health gradient. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
96.
Silas Alben Kevin Spears Stephen Garth David Murphy Jeannette Yen 《Journal of the Royal Society Interface》2010,7(52):1545-1557
Krill are aquatic crustaceans that engage in long distance migrations, either vertically in the water column or horizontally for 10 km (over 200 000 body lengths) per day. Hence efficient locomotory performance is crucial for their survival. We study the swimming kinematics of krill using a combination of experiment and analysis. We quantify the propulsor kinematics for tethered and freely swimming krill in experiments, and find kinematics that are very nearly metachronal. We then formulate a drag coefficient model which compares metachronal, synchronous and intermediate motions for a freely swimming body with two legs. With fixed leg velocity amplitude, metachronal kinematics give the highest average body speed for both linear and quadratic drag laws. The same result holds for five legs with the quadratic drag law. When metachronal kinematics is perturbed towards synchronous kinematics, an analysis shows that the velocity increase on the power stroke is outweighed by the velocity decrease on the recovery stroke. With fixed time-averaged work done by the legs, metachronal kinematics again gives the highest average body speed, although the advantage over synchronous kinematics is reduced. 相似文献
97.
Wendy Jeannette Van Der Spuy Etheresia Pretorius 《Microscopy research and technique》2013,76(8):795-802
It is well known that estrogen is neuroprotective through various mechanisms which suggest that sex hormone levels, thrombotic mechanisms, and inflammatory processes are strongly interconnected in predicting the outcome and consequences of cerebral ischemia. Because platelet ultrastructure is altered in conditions like thrombosis and associated with stroke, the question arises whether ultrastructural analyses of platelet morphology may provide further insight into the role of estrogen during ischemic insult. In the current study, a hyperglycemic modification to the two‐vessel occlusion model for inducing experimental cerebral ischemia was employed, in order to correlate neural tissue integrity levels between three experimental groups to corresponding platelet ultrastructure so as to determine whether there is an association between cerebral ischemia and the presence of inflammatory or necrotic platelet ultrastructure. It is apparent in the results that under the influence of estrogen in cyclic or intact females, there is lesser neural tissue damage as well as a reduced degree of inflammation evident in platelet activation morphology when compared to males and acyclic or ovariectomized females. It is unmistakable that neural injury is closely shadowed, if not preceded, by inflammatory changes in the coagulation system, particularly manifested in platelet ultrastructure. It is therefore suggested that platelets may indeed be used successfully to follow the progression of events of cerebral ischemia and possibly assist in the assessment of treatment strategies and their effects on hemostasis. Microsc. Res. Tech. 76:795–802, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
98.
Candy Yuriria Ramírez-Zavaleta Laura Jeannette García-Barrera Lizette Liliana Rodríguez-Verstegui Daniela Arrieta-Flores Josefat Gregorio-Jorge 《International journal of molecular sciences》2022,23(21)
Cell-surface-localized pattern recognition receptors (PRRs) and intracellular nucleotide-binding domain and leucine-rich repeat receptors (NLRs) are plant immune proteins that trigger an orchestrated downstream signaling in response to molecules of microbial origin or host plant origin. Historically, PRRs have been associated with pattern-triggered immunity (PTI), whereas NLRs have been involved with effector-triggered immunity (ETI). However, recent studies reveal that such binary distinction is far from being applicable to the real world. Although the perception of plant pathogens and the final mounting response are achieved by different means, central hubs involved in signaling are shared between PTI and ETI, blurring the zig-zag model of plant immunity. In this review, we not only summarize our current understanding of PRR- and NLR-mediated immunities in plants, but also highlight those signaling components that are evolutionarily conserved across the plant kingdom. Altogether, we attempt to offer an overview of how plants mediate and integrate the induction of the defense responses that comprise PTI and ETI, emphasizing the need for more evolutionary molecular plant–microbe interactions (EvoMPMI) studies that will pave the way to a better understanding of the emergence of the core molecular machinery involved in the so-called evolutionary arms race between plants and microbes. 相似文献
99.
We introduce a new class of random graph models for complex real-world networks, based on the protean graph model by Łuczak and Prałat. Our generalized protean graph models have two distinguishing features. First, they are not growth models, but instead are based on the assumption that a “steady state” of large but finite size has been reached. Second, the models assume that the vertices are ranked according to a given ranking scheme, and the rank of a vertex determines the probability that that vertex receives a link in a given time step. Precisely, the link probability is proportional to the rank raised to the power −α, where the attachment strength α is a tunable parameter. We show that the model leads to a power law degree distribution with exponent 1+1/α for ranking schemes based on a given prestige label, or on the degree of a vertex. We also study a scheme where each vertex receives an initial rank chosen randomly according to a biased distribution. In this case, the degree distribution depends on the distribution of the initial rank. For one particular choice of parameters we obtain a power law with an exponent that depends both on α and on a parameter determining the initial rank distribution. 相似文献
100.
Jeannette Østergaard Penny Merete Brink Speedtsberg Thomas Kallemose Jesper Bencke 《Ergonomics》2018,61(8):1130-1138
The study sought to investigate whether an orthotic stiletto could modulate the pressure and comfort under the forefoot, arch and heel that stiletto wearers experience. Twenty-two women participated. We measured the peak pressure and pressure-time integral for orthotic stilettos with built-in metatarsal pad, heel cup and arch support; standard stilettos without inlays; and trainers. Comfort was recorded during 3 × 3 working days. The orthotic stiletto exhibited lower metatarsal head1 (MTH) and MTH2+3 and heel pressures than the standard stiletto (p < .01), and a long second metatarsal increased MTH2+3 pressure (p < .01). The comfort in the forefoot and heel was higher in the orthotic stiletto than in the standard one (p < .01), and comfort in the forefoot was correlated to the pressure-time integral of MTH2+3 (p = .03) and not peak pressure. Off-the-rack orthotic stilettos can notably reduce plantar pressures and improve forefoot and heel comfort during everyday use.
Practitioner Summary: Off-the-rack orthotic stilettos with built-in metatarsal pad, arch support and heel caps can lower the pressure under the heel and forefoot in comparison with a standard stiletto and can improve comfort during everyday use. Having a long second metatarsal is a risk factor for increased forefoot pressure. 相似文献