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排序方式: 共有1019条查询结果,搜索用时 16 毫秒
71.
The thermodynamic data for LaNi4.25Al0.75 tritide, reported by Wang et al. (W.-d. Wang et al., J. Alloys Compd. (2006), doi:10.1016/j.jallcom.206.09.122), are in variance with our published data. The plateau pressures for the P–C–T isotherms at all temperatures are significantly lower than published data. As a result, the derived thermodynamic parameters, ΔH° and ΔS°, are questionable. Using the thermodynamic parameters derived from the data reported by Wang et al. will result in under estimating the expected pressures, and therefore not to provide the desired performance for storing and processing tritium. 相似文献
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73.
Protein structure alignment by incremental combinatorial extension (CE) of the optimal path 总被引:19,自引:0,他引:19
A new algorithm is reported which builds an alignment between two protein
structures. The algorithm involves a combinatorial extension (CE) of an
alignment path defined by aligned fragment pairs (AFPs) rather than the
more conventional techniques using dynamic programming and Monte Carlo
optimization. AFPs, as the name suggests, are pairs of fragments, one from
each protein, which confer structure similarity. AFPs are based on local
geometry, rather than global features such as orientation of secondary
structures and overall topology. Combinations of AFPs that represent
possible continuous alignment paths are selectively extended or discarded
thereby leading to a single optimal alignment. The algorithm is fast and
accurate in finding an optimal structure alignment and hence suitable for
database scanning and detailed analysis of large protein families. The
method has been tested and compared with results from Dali and VAST using a
representative sample of similar structures. Several new structural
similarities not detected by these other methods are reported. Specific
one-on-one alignments and searches against all structures as found in the
Protein Data Bank (PDB) can be performed via the Web at
http://cl.sdsc.edu/ce.html.
相似文献
74.
Bennett CM Dharmage SC Matheson M Gras JL Markos J Mészáros D Hopper J Walters EH Abramson MJ 《The Science of the total environment》2010,409(2):294-299
Wood smoke exposure has been associated with adverse respiratory health outcomes, with much of the current research focused on wood smoke from domestic heating and cooking. This study examined the association between respiratory symptoms and outdoor wood smoke in Launceston, Tasmania, where ~ 30% of homes use wood burners for domestic heating. This ecological study examined data from participants of the 2004 Tasmanian Longitudinal Health Study postal survey and compared the prevalence of respiratory symptoms in Launceston (n = 601) with that in Hobart (n = 1071), a larger Tasmanian city with much less wood smoke. Multivariate logistic regression models were used to investigate the associations of interest while adjusting for gender, atopy, history of allergic disease and current smoking status. There were no significant differences in symptom prevalence between Launceston and Hobart. Two subgroup analyses, which examined participants with pre-existing chronic respiratory disease, and those who reported actively using a wood burner in their home, also did not find significant differences. Any impact of wood smoke on non-specific respiratory symptoms might have been overshadowed by other important determinants of respiratory health, such as vehicle exhaust and tobacco smoking, or were too small to have been detected. However, the lack of detectable differences in symptom prevalence might also reflect the success of regulatory action by local governments to reduce wood smoke emissions in Launceston. The results of other epidemiological studies support an association between ambient wood smoke exposure and adverse respiratory health. Further investigations of wood smoke exposure in Australian settings are needed to investigate the lack of significant associations found in this study, especially studies of indoor air quality and health impacts in children and elderly populations. 相似文献
75.
Karen A. Blocksom David M. Walters Terri M. Jicha Theodore R. Angradi 《The Science of the total environment》2010,408(5):1180-539
Great rivers of the central United States (Upper Mississippi, Missouri, and Ohio rivers) are valuable economic and cultural resources, yet until recently their ecological condition has not been well quantified. In 2004-2005, as part of the Environmental Monitoring and Assessment Program for Great River Ecosystems (EMAP-GRE), we measured legacy organochlorines (OCs) (pesticides and polychlorinated biphenyls, PCBs) and emerging compounds (polybrominated diphenyl ethers, PBDEs) in whole fish to estimate human and wildlife exposure risks from fish consumption. PCBs, PBDEs, chlordane, dieldrin and dichlorodiphenyltrichloroethane (DDT) were detected in most samples across all rivers, and hexachlorobenzene was detected in most Ohio River samples. Concentrations were highest in the Ohio River, followed by the Mississippi and Missouri Rivers, respectively. Dieldrin and PCBs posed the greatest risk to humans. Their concentrations exceeded human screening values for cancer risk in 27-54% and 16-98% of river km, respectively. Chlordane exceeded wildlife risk values for kingfisher in 11-96% of river km. PBDE concentrations were highest in large fish in the Missouri and Ohio Rivers (mean > 1000 ng g− 1 lipid), with congener 47 most prevalent. OC and PBDE concentrations were positively related to fish size, lipid content, trophic guild, and proximity to urban areas. Contamination of fishes by OCs is widespread among great rivers, although exposure risks appear to be more localized and limited in scope. As an indicator of ecological condition, fish tissue contamination contributes to the overall assessment of great river ecosystems in the U.S. 相似文献
76.
Walters C. L. Burger I. H. Jewell G. G. Lewis D. F. Parke D. V. 《European Food Research and Technology》1975,159(4):193-203
European Food Research and Technology - The velocity of oxidation of exogeneous ferrocytochrome c by nitrite under anaerobic conditions in the presence of skeletal muscle mitochondria is dependent... 相似文献
77.
78.
79.
Zachary B. Walters 《Computer Physics Communications》2011,(4):935-939
This paper presents a new technique to calculate the evolution of a quantum wavefunction in a chosen spatial basis by minimizing the accumulated action. Introduction of a finite temporal basis reduces the problem to a set of linear equations, while an appropriate choice of temporal basis set offers improved convergence relative to methods based on matrix exponentiation for a class of physically relevant problems. 相似文献
80.
Elyse H. Milun Deborah K. W. Walters Yiming Li Bemina Atanacio 《Computer Vision and Image Understanding》1999,76(3):259
General ribbons are presented as a mathematical model of stylus-generated images which is based on the image formation process. One purpose of the model is to provide a formal basis for the development of thinning algorithms for the stroke components of stylus-generated images. Before the stroke components can be thinned they must be segmented from the blob components of the image, which do not require thinning. The second purpose of the model is to provide a formal basis for the development of blob/stroke segmentation algorithms. Two blob/stroke segmentation algorithms based on the model are presented. 相似文献