全文获取类型
收费全文 | 74篇 |
免费 | 1篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 9篇 |
机械仪表 | 1篇 |
建筑科学 | 4篇 |
能源动力 | 1篇 |
轻工业 | 9篇 |
石油天然气 | 1篇 |
无线电 | 4篇 |
一般工业技术 | 8篇 |
冶金工业 | 25篇 |
自动化技术 | 8篇 |
出版年
2019年 | 2篇 |
2017年 | 1篇 |
2014年 | 1篇 |
2013年 | 5篇 |
2011年 | 6篇 |
2010年 | 2篇 |
2009年 | 1篇 |
2008年 | 2篇 |
2007年 | 5篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1955年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有75条查询结果,搜索用时 984 毫秒
1.
A middle-aged woman presented with recent-onset left hemiparesis and right subclavian steal syndrome. She was found to have an obstructed innominate artery. We successfully performed balloon angioplasty of the occluded innominate artery and encountered no complications during follow-up of currently 8 months. 相似文献
2.
BK Berdiev KH Karlson B Jovov PJ Ripoll R Morris D Loffing-Cueni P Halpin BA Stanton TR Kleyman II Ismailov 《Canadian Metallurgical Quarterly》1998,75(5):2292-2301
The molecular composition of a core conduction element formed by the alpha-subunit of cloned epithelial Na+ channels (ENaC) was studied in planar lipid bilayers. Two pairs of in vitro translated proteins were employed in combinatorial experiments: 1) wild-type (WT) and an N-terminally truncated alphaDeltaN-rENaC that displays accelerated kinetics (tauo = 32 +/- 13 ms, tauc = 42 +/- 11 ms), as compared with the WT channel (tauc1 = 18 +/- 8 ms, tauc2 = 252 +/- 31 ms, and tauo = 157 +/- 43 ms); and 2) WT and an amiloride binding mutant, alphaDelta278-283-rENaC. The channels that formed in a alphaWT:alphaDeltaN mixture fell into two groups: one with tauo and tauc that corresponded to those exhibited by the alphaDeltaN-rENaC alone, and another with a double-exponentially distributed closed time and a single-exponentially distributed open time that corresponded to the alphaWT-rENaC alone. Five channel subtypes with distinct sensitivities to amiloride were found in a 1alphaWT:1alphaDelta278-283 protein mixture. Statistical analyses of the distributions of channel phenotypes observed for either set of the WT:mutant combinations suggest a tetrameric organization of alpha-subunits as a minimal model for the core conduction element in ENaCs. 相似文献
3.
R. Sam Williams Steve Lacher Corey Halpin Christopher White 《Materials and Structures》1988,21(4):313-320
RILEM Bulletin
Fourth International Conference on Durability of Building Materials and Components 相似文献4.
M Biernat CS Crandall LV Young D Kobrynowicz SM Halpin 《Canadian Metallurgical Quarterly》1998,75(2):301-317
The authors tested the shifting standards model (M. Biernat, M. Manis, & T. E. Nelson, 1991) as it applies to sex- and race-based stereotyping of self and others in the military. U. S. Army officers attending a leadership training course made judgments of their own and their groupmates' leadership competence at 3 time points over a 9-week period. We examined the effects of officer sex and race on both subjective (rating) and objective/common-rule (ranking/Q-sort) evaluations. Stereotyping generally increased with time, and in accordance with the shifting standards model, pro-male judgment bias was more evident in rankings than in ratings, particularly for White targets. Self-judgments were also affected by sex-based shifting standards, particularly in workgroups containing a single ("solo") woman. Differential standard use on the basis of race was less apparent, a finding attributed to the Army's explicit invocation against the use of differential race-based standards. 相似文献
5.
Jason J. Roberts Benjamin D. Best Daniel C. Dunn Eric A. Treml Patrick N. Halpin 《Environmental Modelling & Software》2010,25(10):1197-1207
With the arrival of GPS, satellite remote sensing, and personal computers, the last two decades have witnessed rapid advances in the field of spatially-explicit marine ecological modeling. But with this innovation has come complexity. To keep up, ecologists must master multiple specialized software packages, such as ArcGIS for display and manipulation of geospatial data, R for statistical analysis, and MATLAB for matrix processing. This requires a costly investment of time and energy learning computer programming, a high hurdle for many ecologists. To provide easier access to advanced analytic methods, we developed Marine Geospatial Ecology Tools (MGET), an extensible collection of powerful, easy-to-use, open-source geoprocessing tools that ecologists can invoke from ArcGIS without resorting to computer programming. Internally, MGET integrates Python, R, MATLAB, and C++, bringing the power of these specialized platforms to tool developers without requiring developers to orchestrate the interoperability between them.In this paper, we describe MGET’s software architecture and the tools in the collection. Next, we present an example application: a habitat model for Atlantic spotted dolphin (Stenella frontalis) that predicts dolphin presence using a statistical model fitted with oceanographic predictor variables. We conclude by discussing the lessons we learned engineering a highly integrated tool framework. 相似文献
6.
7.
This paper presents a strategy for the design and organization of materials for Web‐based instruction (WBI) founded upon cognitive modeling for the identification and organization of the major concepts in the domain of interest, based upon the Pathfinder paradigm. The original purpose of the Pathfinder paradigm was to model aspects of human semantic (associative) memory. A brief introduction to the Pathfinder paradigm is presented, and the rationale for its use in WBI is discussed. The development of this paradigm for WBI, in the context of eliciting and representing knowledge from domain experts, and its use in a pilot study is described. The domain used for the pilot study was the A* search algorithm, embedded within an introductory course in artificial intelligence. Assessment of the paradigm is also discussed, and preliminary methods are applied to the pilot study. 相似文献
8.
Tarek M. Zayed Corresponding author Daniel W. Halpin 《Construction Management & Economics》2013,31(5):531-543
The assessment process of productivity and cost of bored pile construction is dictated by unseen subsurface obstacles, lack of contractor experience and site planning. These problems complicate the estimator's role in evaluating pile equipment productivity and cost. Current research discusses the assessment of piling process productivity and cost using the deterministic technique. Data are collected through questionnaires, site interviews and telephone calls to experts in various construction companies. Many variables have been considered in the piling construction process, such as pile size, depth, pouring method, soil type and construction method. Five deterministic models have been designated to assess productivity, cycle time and cost. The developed models are validated whereas 79% of the outputs have been predicted with more than 75% accuracy. Consequently, three sets of charts have been developed to provide the decision‐maker with a solid planning, scheduling and control tool for piling projects. If a pile has 60′ depth with φ‐18 (18″ diameter pile) in clay soil using a 5′ auger height, the cycle time is estimated as 56 and 65.5 minutes; however, productivity is 6 and 5 holes/day for dry and wet methods, respectively. 相似文献
9.
Dental caries is a highly prevalent disease caused by colonisation of tooth surfaces by cariogenic bacteria, such as Streptococcus sobrinus and Streptococcus salivarius. Reducing initial adherence of such bacteria to teeth may delay onset of caries. Many foods, such as milk, can inhibit microbial adherence. In this investigation, the effect of untreated (UT) and enzyme-treated (ET) dairy powders on adherence of S. sobrinus and S. salivarius to hydroxylapatite (HA), an analogue of tooth enamel, was examined. Untreated (UT) acid whey protein concentrate (AWPC) 80 inhibited streptococcal adherence to phosphate-buffered saline-coated HA (PBS-HA) and saliva-coated HA (S-HA) by >80% at ?31.25 μg mL−1. UT sweet WPC80, buttermilk powder and cream powder also significantly reduced adherence (P < 0.05). Enzyme-treatment of all dairy powders reduced their anti-adhesion activity. However, ET sweet WPC80 significantly inhibited growth of these streptococci (P < 0.05) at ?0.6 mg mL−1. Therefore, dairy powders may reduce progression of dental caries by their anti-adhesion and/or antibacterial activity. 相似文献
10.
IM Bell JM Erb RM Freidinger SN Gallicchio JP Guare MT Guidotti RA Halpin DW Hobbs CF Homnick MS Kuo EV Lis DJ Mathre SR Michelson JM Pawluczyk DJ Pettibone DR Reiss S Vickers PD Williams CJ Woyden 《Canadian Metallurgical Quarterly》1998,41(12):2146-2163
The previously reported oxytocin antagonist L-371,257 (2) has been modified at its acetylpiperidine terminus to incorporate various pyridine N-oxide groups. This modification has led to the identification of compounds with improved pharmacokinetics and excellent oral bioavailability. The pyridine N-oxide series is exemplified by L-372,662 (30), which possessed good potency in vitro (Ki = 4.1 nM, cloned human oxytocin receptor) and in vivo (intravenous AD50 = 0.71 mg/kg in the rat), excellent oral bioavailability (90% in the rat, 96% in the dog), good aqueous solubility (>8.5 mg/mL at pH 5.2) which should facilitate formulation for iv administration, and excellent selectivity against the human arginine vasopressin receptors. Incorporation of a 5-fluoro substituent on the central benzoyl ring of this class of oxytocin antagonists enhanced in vitro and in vivo potency but was detrimental to the pharmacokinetic profiles of these compounds. Although lipophilic substitution around the pyridine ring of compound 30 gave higher affinity in vitro, such substituents were a metabolic liability and caused shortfalls in vivo. Two approaches to prevent this metabolism, addition of a cyclic constraint and incorporation of trifluoromethyl groups, were examined. The former approach was ineffective because of metabolic hydroxylation on the constrained ring system, whereas the latter showed improvement in plasma pharmacokinetics in some cases. 相似文献