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51.
Valerie Barr 《Annals of Software Engineering》1997,4(1):171-189
In this paper we discuss ways in which coverage analysis, obtained during execution of test cases over a rule‐base, can be
used to highlight problems in both the test suite and the rule‐base, thereby pointing to areas in which we cannot guarantee
or predict the system’s performance. In particular, we present a series of heuristics which use coverage information and meta‐knowledge
about the larger population to select additional test cases from the population, in the event that the initial test set is
incomplete. This forms the basis of an incremental approach to rule‐base testing which allows us to both increase completeness
of the test set and improve coverage of the rule‐base, thereby increasing the kinds of cases for which the rule‐base has been
executed during testing. We demonstrate this heuristic approach to test data selection using information generated by TRUBAC,
a tool which implements the coverage analysis methods, applied to analyze a prototype system for diagnosis of rheumatological
diseases. 相似文献
52.
William T. Riley Steven C. Carson Norman Martin Albert Behar Valerie L. Forman-Hoffman Albert Jerome 《Computers in human behavior》2005,21(6):1005-1018
This study sought to evaluate the feasibility of a researcher configurable self-monitoring program. An initial prototype of the program was developed as a Windows-based drag and drop flow chart interface for the researcher to construct the self-monitoring or diary protocol to be scheduled and displayed to the subject on a Pocket PC. The usability of the desktop researcher interface was evaluated in a small sample of medication trial researchers whose ratings of the prototype were generally positive and provided directions for improvement. The subject interface was then evaluated in an “analog” drug trial of 49 smokers using nicotine gum. These subjects were randomly assigned to either paper-based log or Pocket PC self-monitoring for 3 weeks. Pocket PC subjects were significantly more compliant than the log subjects on recording in the second (65% vs. 39%) and third (69% vs. 39%) weeks of the trial but did not differ from the log condition on total recording entries, likely due to the restrictions on retrospective recording in the Pocket PC program. This study provides support for the feasibility of a researcher configurable electronic diary system which should substantially reduce the programming barriers to electronic self-monitoring and increase the use of real-time monitoring in clinical and research venues. 相似文献
53.
Experimentally measured contact traces, such as those obtained in a conference setting by using short range wireless sensors, are usually limited with respect to the practical number of sensors that can be deployed as well as the number of available human volunteers. Moreover, most previous experiments in this field can report only partial contact information since not everyone participating in the experiment carries a sensor device. Previously collected contact traces have significantly contributed to the development of more realistic human mobility models. This in turn has influenced proposed routing algorithms for Delay Tolerant Networks where human contacts play a vital role in message delivery. By exploiting time-spatial properties of contact graphs as well as the popularity and social information of mobile nodes, we propose a novel method to reconstruct the missing parts of contact graphs where only a subset of nodes are able to sense contacts. 相似文献
54.
Journal of Signal Processing Systems - 相似文献
55.
The use of dry whole milk, skimmed milk, caseinate, regular and modified whey, at 2% level (w/w) and with 2% additional protein level was studied in a chicken breast meat system with 51% water addition. At the 2% (w/w) level, all dairy proteins significantly reduced cooking loss compared with the control, with caseinate showing the best results. When compared on an equal protein level (2% total protein), the best performing ingredients were the whole milk and modified whey. A similar observation was made in their effect on the products’ hardness and fracturability. A cost analysis revealed that modified whey provided the most economical ingredient even when used in quantities three times greater than that of as caseinate. Microscopy results showed the formation of larger fine‐protein‐matrix regions in the treatments that provided higher fracturability values. 相似文献
56.
The misfolding and aggregation of the prion protein (PrP) is the primary cause of a group of infectious neurodegenerative
diseases including Creutzfeldt-Jacob disease in humans and Bovine Spongiform Encephalopathy in cows. A single disease can
exhibit different infectious strains distinguishable by incubation time and morphology or distribution of the aggregates.
Infected brain tissue from one species can be used to infect other species, but with different efficiencies, suggesting a
spectrum of species compatibility. If PrP is, as widely believed, the sole component of infection, then the species and strain
differences must be accounted for by the structure of the aggregates, likely influenced by each species’ PrP sequence. As
there are no high-resolution data exploring this hypothesis, we performed molecular dynamics simulations of PrP for human,
bovine, hamster, and D147N mutant hamster sequences at low pH to induce misfolding of the protein. We selected representative
converted structures from each of the four sequences and, with the guidance of experimental data, constructed models of the
infectious aggregates. Both hamster monomers showed high flexibility during conversion, suggesting hamster may more easily
adopt altered conformations, which in turn may explain why it is more easily infected by some other species. Human and bovine
aggregates were similar, with monomers docking in P31 symmetry to form a left-handed spiral. In contrast, hamster aggregates formed a P31 right-handed spiral. We detail the differences in the converted monomers that give rise to this difference and show that
our results compare favorably with experimental data.
This paper is part of the special Journal of Materials Science issue Nano- and micromechanical properties of hierarchical biological materials: Linking mechanics, chemistry and biology; Guest
Editor: Markus J. Buehler that appeared in Journal of Materials Science volume 42, issue 21, November 2007. This paper was delayed for nonscientific
reasons. 相似文献
57.
ValerieRachko 《今日电子》2001,(3):13-14
几年以前,高容量的现场可编程器件(FPGA)指 的是包含有5万个门电路,应用于逻辑结合比较紧密的 电路。但今天的FPGA已包含数百万个门电路,成为某 些增长最快的高科技市场的电子系统核心。摩尔定律在FPGA上呈现,包括门数与速率。高容量、高性能的FPGA已处在硅技术的前沿,甚至在某些场合替代了ASIC。 相似文献
58.
Researchers using the hypothesis of cumulative advantages and disadvantages argue that the accumulation of small advantages for men and small disadvantages for women contributes to the gender gap in engineering. This paper uses data from a 1998 survey of engineering undergraduates to test a re‐specification of this hypothesis that treats the gender distribution of advantages and disadvantages as an empirical question. We considered four sets of factors that have been shown to promote choice of an engineering major, persistence in engineering, and progress in engineering: family background, high school participation in mathematics and science, university participation in engineering, and integration into engineering. We found gender differences for each set of factors. We also found that men and women accumulate different advantages and disadvantages as they move through the education pipeline. By demonstrating that the accumulation of advantages and disadvantages is gendered, these results highlight the importance of examining the impact of micro‐inequities on the persistence and progress of men and women in engineering. 相似文献
59.
Kirsten Bomans Thérèse Steenberghen Valerie Dewaelheyns Hans Leinfelder Hubert Gulinck 《Landscape and urban planning》2010,94(3-4):196-205
The open space in Flanders is subjected to different transformation processes. These processes are related to dynamic interactions within an urbanizing society and to competition for space by an increasing number of functions. Despite the acknowledgement of dynamic land use demands, the current categorizations of land use and land cover are not always able to catch transformations related to e.g. newcomers in land use, ecosystem services and multifunctionality in mixed urban–rural areas. Remote sensing tools and census data are insufficient when studying a complex and intensively used space. This research therefore aims to identify underrated transformations in the study area Flanders (the northern part of Belgium) using two main sources: (i) open expert interviews and (ii) three case studies. The interviews serve to formulate a renewed framework that can be used to describe transformations in the open space. The transformation processes that emerge from the interviews and case studies are compared to those defined and recognized in the current spatial planning policy and in existing monitoring data, in order to identify bottlenecks and options for future spatial planning policy. The major conclusions of this paper are (i) a critical view on the analysis and categorization of functions and open space as it is currently practiced in land use monitoring and land use planning programs, (ii) additional data needs to encompass transformation processes in the open space and (iii) the need for a more integral vision for open space. 相似文献
60.
Grain subdivision and recrystallization in oligocrystalline tantalum during cold swaging and subsequent annealing 总被引:1,自引:0,他引:1
Hugo R. Z. Sandim Angelo F. Padilha Valerie Randle Wolfgang Blum 《International Journal of Refractory Metals and Hard Materials》1999,17(6):431-435
A coarse-grained ingot of high-purity tantalum was deformed by swaging at room temperature to a strain of 1.28. During annealing at 900°C for 30 min two neighboring grains were observed to behave quite differently. Electron backscattering diffraction (EBSD) results show noticeable differences in terms of the misorientations developed in both grains. The grain developing larger misorientations recrystallized much more readily than the other. The result is interpreted in terms of the differences in grain subdivision into strongly misoriented regions. 相似文献